Generate setters, but tests are failing

74 files changed, 488 insertions, 430 deletions

diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/ArrayCreationLevel.java b/javaparser-core/src/main/java/com/github/javaparser/ast/ArrayCreationLevel.java
index 3645dcb3d..ef6f32ce8 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/ArrayCreationLevel.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/ArrayCreationLevel.java
@@ -83,7 +83,7 @@ public class ArrayCreationLevel extends Node implements NodeWithAnnotations<Arra
      * @param dimension the dimension, can be null
      * @return this, the ArrayCreationLevel
      */
-    public ArrayCreationLevel setDimension(Expression dimension) {
+    public ArrayCreationLevel setDimension(final Expression dimension) {
         notifyPropertyChange(ObservableProperty.DIMENSION, this.dimension, dimension);
         this.dimension = dimension;
         setAsParentNodeOf(dimension);
@@ -100,10 +100,11 @@ public class ArrayCreationLevel extends Node implements NodeWithAnnotations<Arra
     }
 
     @Override
-    public ArrayCreationLevel setAnnotations(NodeList<AnnotationExpr> annotations) {
+    public ArrayCreationLevel setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
+        this.annotations = annotations;
         setAsParentNodeOf(annotations);
-        this.annotations = assertNotNull(annotations);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/CompilationUnit.java b/javaparser-core/src/main/java/com/github/javaparser/ast/CompilationUnit.java
index dc5d8ffc3..41fddce0a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/CompilationUnit.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/CompilationUnit.java
@@ -161,10 +161,11 @@ public final class CompilationUnit extends Node {
      *
      * @param imports the list of imports
      */
-    public CompilationUnit setImports(NodeList<ImportDeclaration> imports) {
+    public CompilationUnit setImports(final NodeList<ImportDeclaration> imports) {
+        assertNotNull(imports);
         notifyPropertyChange(ObservableProperty.IMPORTS, this.imports, imports);
-        this.imports = assertNotNull(imports);
-        setAsParentNodeOf(this.imports);
+        this.imports = imports;
+        setAsParentNodeOf(imports);
         return this;
     }
 
@@ -183,20 +184,21 @@ public final class CompilationUnit extends Node {
      *
      * @param pakage the packageDeclaration declaration to set or <code>null</code> to default package
      */
-    public CompilationUnit setPackageDeclaration(PackageDeclaration pakage) {
-        notifyPropertyChange(ObservableProperty.PACKAGE_DECLARATION, this.packageDeclaration, pakage);
-        this.packageDeclaration = pakage;
-        setAsParentNodeOf(this.packageDeclaration);
+    public CompilationUnit setPackageDeclaration(final PackageDeclaration packageDeclaration) {
+        notifyPropertyChange(ObservableProperty.PACKAGE_DECLARATION, this.packageDeclaration, packageDeclaration);
+        this.packageDeclaration = packageDeclaration;
+        setAsParentNodeOf(packageDeclaration);
         return this;
     }
 
     /**
      * Sets the list of types declared in this compilation unit.
      */
-    public CompilationUnit setTypes(NodeList<TypeDeclaration<?>> types) {
+    public CompilationUnit setTypes(final NodeList<TypeDeclaration<?>> types) {
+        assertNotNull(types);
         notifyPropertyChange(ObservableProperty.TYPES, this.types, types);
-        this.types = assertNotNull(types);
-        setAsParentNodeOf(this.types);
+        this.types = types;
+        setAsParentNodeOf(types);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/ImportDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/ImportDeclaration.java
index 9046e4b31..a702f0d86 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/ImportDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/ImportDeclaration.java
@@ -27,6 +27,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * An import declaration.
  * <br/><code>import com.github.javaparser.JavaParser;</code>
@@ -90,21 +92,22 @@ public final class ImportDeclaration extends Node implements NodeWithName<Import
         return isStatic;
     }
 
-    public ImportDeclaration setAsterisk(boolean asterisk) {
-        notifyPropertyChange(ObservableProperty.IS_ASTERISK, this.isAsterisk, isAsterisk);
-        this.isAsterisk = asterisk;
+    public ImportDeclaration setAsterisk(final boolean isAsterisk) {
+        notifyPropertyChange(ObservableProperty.ASTERISK, this.isAsterisk, isAsterisk);
+        this.isAsterisk = isAsterisk;
         return this;
     }
 
-    public ImportDeclaration setName(Name name) {
+    public ImportDeclaration setName(final Name name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
         this.name = name;
-        setAsParentNodeOf(this.name);
+        setAsParentNodeOf(name);
         return this;
     }
 
-    public ImportDeclaration setStatic(boolean isStatic) {
-        notifyPropertyChange(ObservableProperty.IS_STATIC, this.isStatic, isStatic);
+    public ImportDeclaration setStatic(final boolean isStatic) {
+        notifyPropertyChange(ObservableProperty.STATIC, this.isStatic, isStatic);
         this.isStatic = isStatic;
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/Node.java b/javaparser-core/src/main/java/com/github/javaparser/ast/Node.java
index 8374d06b3..ddcfcf6ce 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/Node.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/Node.java
@@ -197,17 +197,9 @@ public abstract class Node implements Cloneable, HasParentNode<Node>, Visitable
      * @param comment to be set
      */
     public final Node setComment(final Comment comment) {
-        if (comment != null && (this instanceof Comment)) {
-            throw new RuntimeException("A comment can not be commented");
-        }
         notifyPropertyChange(ObservableProperty.COMMENT, this.comment, comment);
-        if (this.comment != null) {
-            this.comment.setCommentedNode(null);
-        }
         this.comment = comment;
-        if (comment != null) {
-            this.comment.setCommentedNode(this);
-        }
+        setAsParentNodeOf(comment);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/PackageDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/PackageDeclaration.java
index f0682a9ad..554a672ad 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/PackageDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/PackageDeclaration.java
@@ -99,10 +99,11 @@ public final class PackageDeclaration extends Node implements NodeWithAnnotation
      * @param annotations the annotations to set
      */
     @Override
-    public PackageDeclaration setAnnotations(NodeList<AnnotationExpr> annotations) {
+    public PackageDeclaration setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
-        this.annotations = assertNotNull(annotations);
-        setAsParentNodeOf(this.annotations);
+        this.annotations = annotations;
+        setAsParentNodeOf(annotations);
         return this;
     }
 
@@ -112,10 +113,11 @@ public final class PackageDeclaration extends Node implements NodeWithAnnotation
      * @param name the name to set
      */
     @Override
-    public PackageDeclaration setName(Name name) {
+    public PackageDeclaration setName(final Name name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
-        setAsParentNodeOf(this.name);
+        this.name = name;
+        setAsParentNodeOf(name);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/AnnotationMemberDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/AnnotationMemberDeclaration.java
index 70cac014a..238697c5c 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/AnnotationMemberDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/AnnotationMemberDeclaration.java
@@ -128,35 +128,35 @@ public final class AnnotationMemberDeclaration extends BodyDeclaration<Annotatio
      * @param defaultValue the default value, can be null
      * @return this, the AnnotationMemberDeclaration
      */
-    public AnnotationMemberDeclaration setDefaultValue(Expression defaultValue) {
+    public AnnotationMemberDeclaration setDefaultValue(final Expression defaultValue) {
         notifyPropertyChange(ObservableProperty.DEFAULT_VALUE, this.defaultValue, defaultValue);
-        if (this.defaultValue != null) {
-            this.defaultValue.setParentNode(null);
-        }
         this.defaultValue = defaultValue;
         setAsParentNodeOf(defaultValue);
         return this;
     }
 
     @Override
-    public AnnotationMemberDeclaration setModifiers(EnumSet<Modifier> modifiers) {
+    public AnnotationMemberDeclaration setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return this;
     }
 
     @Override
-    public AnnotationMemberDeclaration setName(SimpleName name) {
+    public AnnotationMemberDeclaration setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
 
     @Override
-    public AnnotationMemberDeclaration setType(Type type) {
+    public AnnotationMemberDeclaration setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
-        this.type = assertNotNull(type);
+        this.type = type;
         setAsParentNodeOf(type);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/BodyDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/BodyDeclaration.java
index 2c13d4701..5affb36b7 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/BodyDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/BodyDeclaration.java
@@ -63,10 +63,11 @@ public abstract class BodyDeclaration<T extends Node> extends Node implements No
      */
     @SuppressWarnings("unchecked")
     @Override
-    public final T setAnnotations(NodeList<AnnotationExpr> annotations) {
+    public final T setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
-        this.annotations = assertNotNull(annotations);
-        setAsParentNodeOf(this.annotations);
+        this.annotations = annotations;
+        setAsParentNodeOf(annotations);
         return (T) this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/ClassOrInterfaceDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/ClassOrInterfaceDeclaration.java
index 9b6049bee..36e32bfc2 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/ClassOrInterfaceDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/ClassOrInterfaceDeclaration.java
@@ -103,32 +103,35 @@ public final class ClassOrInterfaceDeclaration extends TypeDeclaration<ClassOrIn
     }
 
     @Override
-    public ClassOrInterfaceDeclaration setExtendedTypes(final NodeList<ClassOrInterfaceType> extendsList) {
-        notifyPropertyChange(ObservableProperty.EXTENDED_TYPES, this.extendedTypes, extendsList);
-        this.extendedTypes = assertNotNull(extendsList);
-        setAsParentNodeOf(this.extendedTypes);
+    public ClassOrInterfaceDeclaration setExtendedTypes(final NodeList<ClassOrInterfaceType> extendedTypes) {
+        assertNotNull(extendedTypes);
+        notifyPropertyChange(ObservableProperty.EXTENDED_TYPES, this.extendedTypes, extendedTypes);
+        this.extendedTypes = extendedTypes;
+        setAsParentNodeOf(extendedTypes);
         return this;
     }
 
     @Override
-    public ClassOrInterfaceDeclaration setImplementedTypes(final NodeList<ClassOrInterfaceType> implementsList) {
-        notifyPropertyChange(ObservableProperty.IMPLEMENTED_TYPES, this.implementedTypes, implementsList);
-        this.implementedTypes = assertNotNull(implementsList);
-        setAsParentNodeOf(this.implementedTypes);
+    public ClassOrInterfaceDeclaration setImplementedTypes(final NodeList<ClassOrInterfaceType> implementedTypes) {
+        assertNotNull(implementedTypes);
+        notifyPropertyChange(ObservableProperty.IMPLEMENTED_TYPES, this.implementedTypes, implementedTypes);
+        this.implementedTypes = implementedTypes;
+        setAsParentNodeOf(implementedTypes);
         return this;
     }
 
-    public ClassOrInterfaceDeclaration setInterface(final boolean interface_) {
-        notifyPropertyChange(ObservableProperty.IS_INTERFACE, this.isInterface, interface_);
-        this.isInterface = interface_;
+    public ClassOrInterfaceDeclaration setInterface(final boolean isInterface) {
+        notifyPropertyChange(ObservableProperty.INTERFACE, this.isInterface, isInterface);
+        this.isInterface = isInterface;
         return this;
     }
 
     @Override
     public ClassOrInterfaceDeclaration setTypeParameters(final NodeList<TypeParameter> typeParameters) {
+        assertNotNull(typeParameters);
         notifyPropertyChange(ObservableProperty.TYPE_PARAMETERS, this.typeParameters, typeParameters);
-        this.typeParameters = assertNotNull(typeParameters);
-        setAsParentNodeOf(this.typeParameters);
+        this.typeParameters = typeParameters;
+        setAsParentNodeOf(typeParameters);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/ConstructorDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/ConstructorDeclaration.java
index edd8aa79e..7d3e01858 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/ConstructorDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/ConstructorDeclaration.java
@@ -125,41 +125,46 @@ public final class ConstructorDeclaration extends BodyDeclaration<ConstructorDec
     }
 
     @Override
-    public ConstructorDeclaration setModifiers(EnumSet<Modifier> modifiers) {
+    public ConstructorDeclaration setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return this;
     }
 
     @Override
-    public ConstructorDeclaration setName(SimpleName name) {
+    public ConstructorDeclaration setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
-        setAsParentNodeOf(this.name);
+        this.name = name;
+        setAsParentNodeOf(name);
         return this;
     }
 
     @Override
-    public ConstructorDeclaration setParameters(NodeList<Parameter> parameters) {
+    public ConstructorDeclaration setParameters(final NodeList<Parameter> parameters) {
+        assertNotNull(parameters);
         notifyPropertyChange(ObservableProperty.PARAMETERS, this.parameters, parameters);
-        this.parameters = assertNotNull(parameters);
-        setAsParentNodeOf(this.parameters);
+        this.parameters = parameters;
+        setAsParentNodeOf(parameters);
         return this;
     }
 
     @Override
-    public ConstructorDeclaration setThrownExceptions(NodeList<ReferenceType> thrownExceptions) {
-        notifyPropertyChange(ObservableProperty.THROWN_TYPES, this.thrownExceptions, thrownExceptions);
-        this.thrownExceptions = assertNotNull(thrownExceptions);
-        setAsParentNodeOf(this.thrownExceptions);
+    public ConstructorDeclaration setThrownExceptions(final NodeList<ReferenceType> thrownExceptions) {
+        assertNotNull(thrownExceptions);
+        notifyPropertyChange(ObservableProperty.THROWN_EXCEPTIONS, this.thrownExceptions, thrownExceptions);
+        this.thrownExceptions = thrownExceptions;
+        setAsParentNodeOf(thrownExceptions);
         return this;
     }
 
     @Override
-    public ConstructorDeclaration setTypeParameters(NodeList<TypeParameter> typeParameters) {
+    public ConstructorDeclaration setTypeParameters(final NodeList<TypeParameter> typeParameters) {
+        assertNotNull(typeParameters);
         notifyPropertyChange(ObservableProperty.TYPE_PARAMETERS, this.typeParameters, typeParameters);
-        this.typeParameters = assertNotNull(typeParameters);
-        setAsParentNodeOf(this.typeParameters);
+        this.typeParameters = typeParameters;
+        setAsParentNodeOf(typeParameters);
         return this;
     }
 
@@ -224,8 +229,10 @@ public final class ConstructorDeclaration extends BodyDeclaration<ConstructorDec
     }
 
     @Override
-    public ConstructorDeclaration setBody(BlockStmt body) {
-        this.body = assertNotNull(body);
+    public ConstructorDeclaration setBody(final BlockStmt body) {
+        assertNotNull(body);
+        notifyPropertyChange(ObservableProperty.BODY, this.body, body);
+        this.body = body;
         setAsParentNodeOf(body);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumConstantDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumConstantDeclaration.java
index 8a0eef3c1..10058c37b 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumConstantDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumConstantDeclaration.java
@@ -94,24 +94,27 @@ public final class EnumConstantDeclaration extends BodyDeclaration<EnumConstantD
         return name;
     }
 
-    public EnumConstantDeclaration setArguments(NodeList<Expression> arguments) {
+    public EnumConstantDeclaration setArguments(final NodeList<Expression> arguments) {
+        assertNotNull(arguments);
         notifyPropertyChange(ObservableProperty.ARGUMENTS, this.arguments, arguments);
-        this.arguments = assertNotNull(arguments);
-        setAsParentNodeOf(this.arguments);
+        this.arguments = arguments;
+        setAsParentNodeOf(arguments);
         return this;
     }
 
-    public EnumConstantDeclaration setClassBody(NodeList<BodyDeclaration<?>> classBody) {
+    public EnumConstantDeclaration setClassBody(final NodeList<BodyDeclaration<?>> classBody) {
+        assertNotNull(classBody);
         notifyPropertyChange(ObservableProperty.CLASS_BODY, this.classBody, classBody);
-        this.classBody = assertNotNull(classBody);
-        setAsParentNodeOf(this.classBody);
+        this.classBody = classBody;
+        setAsParentNodeOf(classBody);
         return this;
     }
 
     @Override
-    public EnumConstantDeclaration setName(SimpleName name) {
+    public EnumConstantDeclaration setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumDeclaration.java
index 6f6d4c9b6..34240424a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/EnumDeclaration.java
@@ -101,18 +101,20 @@ public final class EnumDeclaration extends TypeDeclaration<EnumDeclaration> impl
         return implementedTypes;
     }
 
-    public EnumDeclaration setEntries(NodeList<EnumConstantDeclaration> entries) {
+    public EnumDeclaration setEntries(final NodeList<EnumConstantDeclaration> entries) {
+        assertNotNull(entries);
         notifyPropertyChange(ObservableProperty.ENTRIES, this.entries, entries);
-        this.entries = assertNotNull(entries);
-        setAsParentNodeOf(this.entries);
+        this.entries = entries;
+        setAsParentNodeOf(entries);
         return this;
     }
 
     @Override
-    public EnumDeclaration setImplementedTypes(NodeList<ClassOrInterfaceType> implementsList) {
-        notifyPropertyChange(ObservableProperty.IMPLEMENTED_TYPES, this.implementedTypes, implementsList);
-        this.implementedTypes = assertNotNull(implementsList);
-        setAsParentNodeOf(this.implementedTypes);
+    public EnumDeclaration setImplementedTypes(final NodeList<ClassOrInterfaceType> implementedTypes) {
+        assertNotNull(implementedTypes);
+        notifyPropertyChange(ObservableProperty.IMPLEMENTED_TYPES, this.implementedTypes, implementedTypes);
+        this.implementedTypes = implementedTypes;
+        setAsParentNodeOf(implementedTypes);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/FieldDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/FieldDeclaration.java
index b88608920..1fdf4773f 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/FieldDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/FieldDeclaration.java
@@ -117,17 +117,19 @@ public final class FieldDeclaration extends BodyDeclaration<FieldDeclaration> im
     }
 
     @Override
-    public FieldDeclaration setModifiers(EnumSet<Modifier> modifiers) {
+    public FieldDeclaration setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return this;
     }
 
     @Override
-    public FieldDeclaration setVariables(NodeList<VariableDeclarator> variables) {
+    public FieldDeclaration setVariables(final NodeList<VariableDeclarator> variables) {
+        assertNotNull(variables);
         notifyPropertyChange(ObservableProperty.VARIABLES, this.variables, variables);
-        this.variables = assertNotNull(variables);
-        setAsParentNodeOf(this.variables);
+        this.variables = variables;
+        setAsParentNodeOf(variables);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/InitializerDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/InitializerDeclaration.java
index a3fc1d764..b8ec07f9f 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/InitializerDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/InitializerDeclaration.java
@@ -79,15 +79,16 @@ public final class InitializerDeclaration extends BodyDeclaration<InitializerDec
         return isStatic;
     }
 
-    public InitializerDeclaration setBody(BlockStmt body) {
-        notifyPropertyChange(ObservableProperty.BLOCK, this.body, body);
-        this.body = assertNotNull(body);
-        setAsParentNodeOf(this.body);
+    public InitializerDeclaration setBody(final BlockStmt body) {
+        assertNotNull(body);
+        notifyPropertyChange(ObservableProperty.BODY, this.body, body);
+        this.body = body;
+        setAsParentNodeOf(body);
         return this;
     }
 
-    public InitializerDeclaration setStatic(boolean isStatic) {
-        notifyPropertyChange(ObservableProperty.IS_STATIC, this.isStatic, isStatic);
+    public InitializerDeclaration setStatic(final boolean isStatic) {
+        notifyPropertyChange(ObservableProperty.STATIC, this.isStatic, isStatic);
         this.isStatic = isStatic;
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/MethodDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/MethodDeclaration.java
index 7daad2ba9..7577e0264 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/MethodDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/MethodDeclaration.java
@@ -149,38 +149,42 @@ public final class MethodDeclaration extends BodyDeclaration<MethodDeclaration>
     public MethodDeclaration setBody(final BlockStmt body) {
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
         this.body = body;
-        setAsParentNodeOf(this.body);
+        setAsParentNodeOf(body);
         return this;
     }
 
     @Override
     public MethodDeclaration setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return this;
     }
 
     @Override
     public MethodDeclaration setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
-        setAsParentNodeOf(this.name);
+        this.name = name;
+        setAsParentNodeOf(name);
         return this;
     }
 
     @Override
     public MethodDeclaration setParameters(final NodeList<Parameter> parameters) {
+        assertNotNull(parameters);
         notifyPropertyChange(ObservableProperty.PARAMETERS, this.parameters, parameters);
-        this.parameters = assertNotNull(parameters);
-        setAsParentNodeOf(this.parameters);
+        this.parameters = parameters;
+        setAsParentNodeOf(parameters);
         return this;
     }
 
     @Override
     public MethodDeclaration setThrownExceptions(final NodeList<ReferenceType> thrownExceptions) {
-        notifyPropertyChange(ObservableProperty.THROWN_TYPES, this.thrownExceptions, thrownExceptions);
-        this.thrownExceptions = assertNotNull(thrownExceptions);
-        setAsParentNodeOf(this.thrownExceptions);
+        assertNotNull(thrownExceptions);
+        notifyPropertyChange(ObservableProperty.THROWN_EXCEPTIONS, this.thrownExceptions, thrownExceptions);
+        this.thrownExceptions = thrownExceptions;
+        setAsParentNodeOf(thrownExceptions);
         return this;
     }
 
@@ -190,17 +194,19 @@ public final class MethodDeclaration extends BodyDeclaration<MethodDeclaration>
     }
 
     @Override
-    public MethodDeclaration setType(Type type) {
+    public MethodDeclaration setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
-        setAsParentNodeOf(this.type);
+        setAsParentNodeOf(type);
         return this;
     }
 
     @Override
     public MethodDeclaration setTypeParameters(final NodeList<TypeParameter> typeParameters) {
+        assertNotNull(typeParameters);
         notifyPropertyChange(ObservableProperty.TYPE_PARAMETERS, this.typeParameters, typeParameters);
-        this.typeParameters = assertNotNull(typeParameters);
+        this.typeParameters = typeParameters;
         setAsParentNodeOf(typeParameters);
         return this;
     }
@@ -209,7 +215,8 @@ public final class MethodDeclaration extends BodyDeclaration<MethodDeclaration>
         return isDefault;
     }
 
-    public MethodDeclaration setDefault(boolean isDefault) {
+    public MethodDeclaration setDefault(final boolean isDefault) {
+        notifyPropertyChange(ObservableProperty.DEFAULT, this.isDefault, isDefault);
         this.isDefault = isDefault;
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/Parameter.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/Parameter.java
index 46f9e3639..32285cf56 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/Parameter.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/Parameter.java
@@ -117,14 +117,15 @@ public final class Parameter extends Node implements NodeWithType<Parameter, Typ
     }
 
     @Override
-    public Parameter setType(Type type) {
+    public Parameter setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
-        setAsParentNodeOf(this.type);
+        setAsParentNodeOf(type);
         return this;
     }
 
-    public Parameter setVarArgs(boolean isVarArgs) {
+    public Parameter setVarArgs(final boolean isVarArgs) {
         notifyPropertyChange(ObservableProperty.VAR_ARGS, this.isVarArgs, isVarArgs);
         this.isVarArgs = isVarArgs;
         return this;
@@ -159,25 +160,28 @@ public final class Parameter extends Node implements NodeWithType<Parameter, Typ
      * so please avoid passing null
      */
     @Override
-    public Parameter setAnnotations(NodeList<AnnotationExpr> annotations) {
+    public Parameter setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
-        this.annotations = assertNotNull(annotations);
-        setAsParentNodeOf(this.annotations);
+        this.annotations = annotations;
+        setAsParentNodeOf(annotations);
         return this;
     }
 
     @Override
-    public Parameter setName(SimpleName name) {
+    public Parameter setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
 
     @Override
-    public Parameter setModifiers(EnumSet<Modifier> modifiers) {
+    public Parameter setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/TypeDeclaration.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/TypeDeclaration.java
index ea9337bd1..b09d80731 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/TypeDeclaration.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/TypeDeclaration.java
@@ -98,26 +98,29 @@ public abstract class TypeDeclaration<T extends Node> extends BodyDeclaration<T>
 
     @SuppressWarnings("unchecked")
     @Override
-    public T setMembers(NodeList<BodyDeclaration<?>> members) {
+    public T setMembers(final NodeList<BodyDeclaration<?>> members) {
+        assertNotNull(members);
         notifyPropertyChange(ObservableProperty.MEMBERS, this.members, members);
-        this.members = assertNotNull(members);
-        setAsParentNodeOf(this.members);
+        this.members = members;
+        setAsParentNodeOf(members);
         return (T) this;
     }
 
     @SuppressWarnings("unchecked")
     @Override
-    public T setModifiers(EnumSet<Modifier> modifiers) {
+    public T setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
-        this.modifiers = assertNotNull(modifiers);
+        this.modifiers = modifiers;
         return (T) this;
     }
 
     @SuppressWarnings("unchecked")
     @Override
-    public T setName(SimpleName name) {
+    public T setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return (T) this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/body/VariableDeclarator.java b/javaparser-core/src/main/java/com/github/javaparser/ast/body/VariableDeclarator.java
index e61db6b7b..e2333949d 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/body/VariableDeclarator.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/body/VariableDeclarator.java
@@ -104,9 +104,10 @@ public final class VariableDeclarator extends Node implements NodeWithType<Varia
     }
 
     @Override
-    public VariableDeclarator setName(SimpleName name) {
+    public VariableDeclarator setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
@@ -117,10 +118,10 @@ public final class VariableDeclarator extends Node implements NodeWithType<Varia
      * @param initializer the initializer expression, can be null
      * @return this, the VariableDeclarator
      */
-    public VariableDeclarator setInitializer(Expression initializer) {
+    public VariableDeclarator setInitializer(final Expression initializer) {
         notifyPropertyChange(ObservableProperty.INITIALIZER, this.initializer, initializer);
         this.initializer = initializer;
-        setAsParentNodeOf(this.initializer);
+        setAsParentNodeOf(initializer);
         return this;
     }
 
@@ -140,10 +141,11 @@ public final class VariableDeclarator extends Node implements NodeWithType<Varia
     }
 
     @Override
-    public VariableDeclarator setType(Type type) {
+    public VariableDeclarator setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
-        setAsParentNodeOf(this.type);
+        setAsParentNodeOf(type);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/comments/Comment.java b/javaparser-core/src/main/java/com/github/javaparser/ast/comments/Comment.java
index 1ac4bf178..1afcc0a06 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/comments/Comment.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/comments/Comment.java
@@ -59,9 +59,10 @@ public abstract class Comment extends Node {
      *
      * @param content the text of the comment to set
      */
-    public Comment setContent(String content) {
+    public Comment setContent(final String content) {
+        assertNotNull(content);
         notifyPropertyChange(ObservableProperty.CONTENT, this.content, content);
-        this.content = assertNotNull(content);
+        this.content = content;
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AnnotationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AnnotationExpr.java
index d473bcd6d..ce101d84b 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AnnotationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AnnotationExpr.java
@@ -53,9 +53,10 @@ public abstract class AnnotationExpr extends Expression implements NodeWithName<
     }
 
     @Override
-    public AnnotationExpr setName(Name name) {
+    public AnnotationExpr setName(final Name name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayAccessExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayAccessExpr.java
index 71d8730dd..9e156e60a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayAccessExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayAccessExpr.java
@@ -72,17 +72,19 @@ public final class ArrayAccessExpr extends Expression {
         return name;
     }
 
-    public ArrayAccessExpr setIndex(Expression index) {
+    public ArrayAccessExpr setIndex(final Expression index) {
+        assertNotNull(index);
         notifyPropertyChange(ObservableProperty.INDEX, this.index, index);
-        this.index = assertNotNull(index);
-        setAsParentNodeOf(this.index);
+        this.index = index;
+        setAsParentNodeOf(index);
         return this;
     }
 
-    public ArrayAccessExpr setName(Expression name) {
+    public ArrayAccessExpr setName(final Expression name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
-        setAsParentNodeOf(this.name);
+        this.name = name;
+        setAsParentNodeOf(name);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayCreationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayCreationExpr.java
index 2530aa38d..483412714 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayCreationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayCreationExpr.java
@@ -100,17 +100,18 @@ public final class ArrayCreationExpr extends Expression {
      * @param initializer the initializer, can be null
      * @return this, the ArrayCreationExpr
      */
-    public ArrayCreationExpr setInitializer(ArrayInitializerExpr initializer) {
+    public ArrayCreationExpr setInitializer(final ArrayInitializerExpr initializer) {
         notifyPropertyChange(ObservableProperty.INITIALIZER, this.initializer, initializer);
         this.initializer = initializer;
-        setAsParentNodeOf(this.initializer);
+        setAsParentNodeOf(initializer);
         return this;
     }
 
-    public ArrayCreationExpr setElementType(Type elementType) {
+    public ArrayCreationExpr setElementType(final Type elementType) {
+        assertNotNull(elementType);
         notifyPropertyChange(ObservableProperty.ELEMENT_TYPE, this.elementType, elementType);
-        this.elementType = assertNotNull(elementType);
-        setAsParentNodeOf(this.elementType);
+        this.elementType = elementType;
+        setAsParentNodeOf(elementType);
         return this;
     }
 
@@ -118,9 +119,10 @@ public final class ArrayCreationExpr extends Expression {
         return levels;
     }
 
-    public ArrayCreationExpr setLevels(NodeList<ArrayCreationLevel> levels) {
+    public ArrayCreationExpr setLevels(final NodeList<ArrayCreationLevel> levels) {
+        assertNotNull(levels);
         notifyPropertyChange(ObservableProperty.LEVELS, this.levels, levels);
-        this.levels = assertNotNull(levels);
+        this.levels = levels;
         setAsParentNodeOf(levels);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayInitializerExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayInitializerExpr.java
index 031a0ef2e..c9490cd62 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayInitializerExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ArrayInitializerExpr.java
@@ -70,10 +70,11 @@ public final class ArrayInitializerExpr extends Expression {
         return values;
     }
 
-    public ArrayInitializerExpr setValues(NodeList<Expression> values) {
+    public ArrayInitializerExpr setValues(final NodeList<Expression> values) {
+        assertNotNull(values);
         notifyPropertyChange(ObservableProperty.VALUES, this.values, values);
-        this.values = assertNotNull(values);
-        setAsParentNodeOf(this.values);
+        this.values = values;
+        setAsParentNodeOf(values);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AssignExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AssignExpr.java
index 137c2d663..9b89e7991 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AssignExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/AssignExpr.java
@@ -26,6 +26,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * An assignment expression. It supports the operators that are found the the AssignExpr.Operator enum.
  * <br/><code>a=5</code>
@@ -94,22 +96,26 @@ public final class AssignExpr extends Expression {
         return value;
     }
 
-    public AssignExpr setOperator(Operator op) {
-        this.operator = op;
+    public AssignExpr setOperator(final Operator operator) {
+        assertNotNull(operator);
+        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, operator);
+        this.operator = operator;
         return this;
     }
 
-    public AssignExpr setTarget(Expression target) {
+    public AssignExpr setTarget(final Expression target) {
+        assertNotNull(target);
         notifyPropertyChange(ObservableProperty.TARGET, this.target, target);
         this.target = target;
-        setAsParentNodeOf(this.target);
+        setAsParentNodeOf(target);
         return this;
     }
 
-    public AssignExpr setValue(Expression value) {
+    public AssignExpr setValue(final Expression value) {
+        assertNotNull(value);
         notifyPropertyChange(ObservableProperty.VALUE, this.value, value);
         this.value = value;
-        setAsParentNodeOf(this.value);
+        setAsParentNodeOf(value);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BinaryExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BinaryExpr.java
index 3b92261b6..7bc493de0 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BinaryExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BinaryExpr.java
@@ -26,6 +26,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * An expression with an expression on the left, an expression on the right, and an operator in the middle.
  * It supports the operators that are found the the BinaryExpr.Operator enum.
@@ -95,23 +97,26 @@ public final class BinaryExpr extends Expression {
         return right;
     }
 
-    public BinaryExpr setLeft(Expression left) {
+    public BinaryExpr setLeft(final Expression left) {
+        assertNotNull(left);
         notifyPropertyChange(ObservableProperty.LEFT, this.left, left);
         this.left = left;
-        setAsParentNodeOf(this.left);
+        setAsParentNodeOf(left);
         return this;
     }
 
-    public BinaryExpr setOperator(Operator op) {
-        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, op);
-        this.operator = op;
+    public BinaryExpr setOperator(final Operator operator) {
+        assertNotNull(operator);
+        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, operator);
+        this.operator = operator;
         return this;
     }
 
-    public BinaryExpr setRight(Expression right) {
+    public BinaryExpr setRight(final Expression right) {
+        assertNotNull(right);
         notifyPropertyChange(ObservableProperty.RIGHT, this.right, right);
         this.right = right;
-        setAsParentNodeOf(this.right);
+        setAsParentNodeOf(right);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BooleanLiteralExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BooleanLiteralExpr.java
index 95dc663cb..d83a85598 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BooleanLiteralExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/BooleanLiteralExpr.java
@@ -65,7 +65,7 @@ public final class BooleanLiteralExpr extends LiteralExpr {
         return value;
     }
 
-    public BooleanLiteralExpr setValue(boolean value) {
+    public BooleanLiteralExpr setValue(final boolean value) {
         notifyPropertyChange(ObservableProperty.VALUE, this.value, value);
         this.value = value;
         return this;
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/CastExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/CastExpr.java
index 6e319268d..3095bbaa8 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/CastExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/CastExpr.java
@@ -78,18 +78,20 @@ public final class CastExpr extends Expression implements NodeWithType<CastExpr,
     }
 
     @Override
-    public CastExpr setExpression(Expression expr) {
-        notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expr);
-        this.expression = assertNotNull(expr);
-        setAsParentNodeOf(this.expression);
+    public CastExpr setExpression(final Expression expression) {
+        assertNotNull(expression);
+        notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
+        this.expression = expression;
+        setAsParentNodeOf(expression);
         return this;
     }
 
     @Override
-    public CastExpr setType(Type type) {
+    public CastExpr setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
-        this.type = assertNotNull(type);
-        setAsParentNodeOf(this.type);
+        this.type = type;
+        setAsParentNodeOf(type);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ClassExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ClassExpr.java
index 0942415e7..aed8f3c0e 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ClassExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ClassExpr.java
@@ -29,6 +29,8 @@ import com.github.javaparser.ast.type.Type;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * Defines an expression that accesses the class of a type.
  * <br/><code>Object.class</code>
@@ -69,10 +71,11 @@ public final class ClassExpr extends Expression implements NodeWithType<ClassExp
     }
 
     @Override
-    public ClassExpr setType(Type type) {
+    public ClassExpr setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
-        setAsParentNodeOf(this.type);
+        setAsParentNodeOf(type);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ConditionalExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ConditionalExpr.java
index 4bb181ce8..b47b9a68d 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ConditionalExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ConditionalExpr.java
@@ -79,24 +79,27 @@ public final class ConditionalExpr extends Expression {
         return thenExpr;
     }
 
-    public ConditionalExpr setCondition(Expression condition) {
+    public ConditionalExpr setCondition(final Expression condition) {
+        assertNotNull(condition);
         notifyPropertyChange(ObservableProperty.CONDITION, this.condition, condition);
-        this.condition = assertNotNull(condition);
-        setAsParentNodeOf(this.condition);
+        this.condition = condition;
+        setAsParentNodeOf(condition);
         return this;
     }
 
-    public ConditionalExpr setElseExpr(Expression elseExpr) {
+    public ConditionalExpr setElseExpr(final Expression elseExpr) {
+        assertNotNull(elseExpr);
         notifyPropertyChange(ObservableProperty.ELSE_EXPR, this.elseExpr, elseExpr);
-        this.elseExpr = assertNotNull(elseExpr);
-        setAsParentNodeOf(this.elseExpr);
+        this.elseExpr = elseExpr;
+        setAsParentNodeOf(elseExpr);
         return this;
     }
 
-    public ConditionalExpr setThenExpr(Expression thenExpr) {
+    public ConditionalExpr setThenExpr(final Expression thenExpr) {
+        assertNotNull(thenExpr);
         notifyPropertyChange(ObservableProperty.THEN_EXPR, this.thenExpr, thenExpr);
-        this.thenExpr = assertNotNull(thenExpr);
-        setAsParentNodeOf(this.thenExpr);
+        this.thenExpr = thenExpr;
+        setAsParentNodeOf(thenExpr);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
index dbc83563b..08fc558db 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/EnclosedExpr.java
@@ -74,7 +74,7 @@ public final class EnclosedExpr extends Expression {
     public EnclosedExpr setInner(final Expression inner) {
         notifyPropertyChange(ObservableProperty.INNER, this.inner, inner);
         this.inner = inner;
-        setAsParentNodeOf(this.inner);
+        setAsParentNodeOf(inner);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/FieldAccessExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/FieldAccessExpr.java
index 3fbbb99f1..c177ce714 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/FieldAccessExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/FieldAccessExpr.java
@@ -85,10 +85,11 @@ public final class FieldAccessExpr extends Expression implements NodeWithSimpleN
     }
 
     @Override
-    public FieldAccessExpr setName(SimpleName name) {
+    public FieldAccessExpr setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
-        setAsParentNodeOf(this.name);
+        this.name = name;
+        setAsParentNodeOf(name);
         return this;
     }
 
@@ -132,7 +133,7 @@ public final class FieldAccessExpr extends Expression implements NodeWithSimpleN
     public FieldAccessExpr setScope(final Expression scope) {
         notifyPropertyChange(ObservableProperty.SCOPE, this.scope, scope);
         this.scope = scope;
-        setAsParentNodeOf(this.scope);
+        setAsParentNodeOf(scope);
         return this;
     }
 
@@ -148,10 +149,10 @@ public final class FieldAccessExpr extends Expression implements NodeWithSimpleN
      * @return this, the FieldAccessExpr
      */
     @Override
-    public FieldAccessExpr setTypeArguments(final NodeList<Type> types) {
+    public FieldAccessExpr setTypeArguments(final NodeList<Type> typeArguments) {
         notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
-        this.typeArguments = types;
-        setAsParentNodeOf(this.typeArguments);
+        this.typeArguments = typeArguments;
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/InstanceOfExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/InstanceOfExpr.java
index b70ab4943..71480e809 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/InstanceOfExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/InstanceOfExpr.java
@@ -80,17 +80,19 @@ public final class InstanceOfExpr extends Expression implements NodeWithType<Ins
 
     @Override
     public InstanceOfExpr setExpression(final Expression expression) {
+        assertNotNull(expression);
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
-        this.expression = assertNotNull(expression);
-        setAsParentNodeOf(this.expression);
+        this.expression = expression;
+        setAsParentNodeOf(expression);
         return this;
     }
 
     @Override
     public InstanceOfExpr setType(final ReferenceType<?> type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
-        this.type = assertNotNull(type);
-        setAsParentNodeOf(this.type);
+        this.type = type;
+        setAsParentNodeOf(type);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/LambdaExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/LambdaExpr.java
index ba2cba595..6cf5c5e0c 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/LambdaExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/LambdaExpr.java
@@ -75,10 +75,11 @@ public class LambdaExpr extends Expression implements NodeWithParameters<LambdaE
     }
 
     @Override
-    public LambdaExpr setParameters(NodeList<Parameter> parameters) {
+    public LambdaExpr setParameters(final NodeList<Parameter> parameters) {
+        assertNotNull(parameters);
         notifyPropertyChange(ObservableProperty.PARAMETERS, this.parameters, parameters);
-        this.parameters = assertNotNull(parameters);
-        setAsParentNodeOf(this.parameters);
+        this.parameters = parameters;
+        setAsParentNodeOf(parameters);
         return this;
     }
 
@@ -86,9 +87,11 @@ public class LambdaExpr extends Expression implements NodeWithParameters<LambdaE
         return body;
     }
 
-    public LambdaExpr setBody(Statement body) {
+    public LambdaExpr setBody(final Statement body) {
+        assertNotNull(body);
+        notifyPropertyChange(ObservableProperty.BODY, this.body, body);
         this.body = body;
-        setAsParentNodeOf(this.body);
+        setAsParentNodeOf(body);
         return this;
     }
 
@@ -106,9 +109,9 @@ public class LambdaExpr extends Expression implements NodeWithParameters<LambdaE
         return isEnclosingParameters;
     }
 
-    public LambdaExpr setEnclosingParameters(boolean enclosingParameters) {
-        notifyPropertyChange(ObservableProperty.ENCLOSING_PARAMETERS, this.isEnclosingParameters, enclosingParameters);
-        this.isEnclosingParameters = enclosingParameters;
+    public LambdaExpr setEnclosingParameters(final boolean isEnclosingParameters) {
+        notifyPropertyChange(ObservableProperty.ENCLOSING_PARAMETERS, this.isEnclosingParameters, isEnclosingParameters);
+        this.isEnclosingParameters = isEnclosingParameters;
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MemberValuePair.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MemberValuePair.java
index 2fdf305fb..b412d6c89 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MemberValuePair.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MemberValuePair.java
@@ -81,16 +81,18 @@ public final class MemberValuePair extends Node implements NodeWithSimpleName<Me
 
     @Override
     public MemberValuePair setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
 
     public MemberValuePair setValue(final Expression value) {
+        assertNotNull(value);
         notifyPropertyChange(ObservableProperty.VALUE, this.value, value);
-        this.value = assertNotNull(value);
-        setAsParentNodeOf(this.value);
+        this.value = value;
+        setAsParentNodeOf(value);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodCallExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodCallExpr.java
index 3e04a90a7..b89983c99 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodCallExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodCallExpr.java
@@ -102,17 +102,19 @@ public final class MethodCallExpr extends Expression implements NodeWithTypeArgu
     }
 
     public MethodCallExpr setArguments(final NodeList<Expression> arguments) {
+        assertNotNull(arguments);
         notifyPropertyChange(ObservableProperty.ARGUMENTS, this.arguments, arguments);
-        this.arguments = assertNotNull(arguments);
-        setAsParentNodeOf(this.arguments);
+        this.arguments = arguments;
+        setAsParentNodeOf(arguments);
         return this;
     }
 
     @Override
     public MethodCallExpr setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
         this.name = name;
-        setAsParentNodeOf(this.name);
+        setAsParentNodeOf(name);
         return this;
     }
 
@@ -120,7 +122,7 @@ public final class MethodCallExpr extends Expression implements NodeWithTypeArgu
     public MethodCallExpr setScope(final Expression scope) {
         notifyPropertyChange(ObservableProperty.SCOPE, this.scope, scope);
         this.scope = scope;
-        setAsParentNodeOf(this.scope);
+        setAsParentNodeOf(scope);
         return this;
     }
 
@@ -139,7 +141,7 @@ public final class MethodCallExpr extends Expression implements NodeWithTypeArgu
     public MethodCallExpr setTypeArguments(final NodeList<Type> typeArguments) {
         notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
         this.typeArguments = typeArguments;
-        setAsParentNodeOf(this.typeArguments);
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodReferenceExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodReferenceExpr.java
index d31f0a64c..f55defa8e 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodReferenceExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/MethodReferenceExpr.java
@@ -33,6 +33,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
 import static com.github.javaparser.utils.Utils.assertNonEmpty;
+import static com.github.javaparser.utils.Utils.assertNotNull;
 
 /**
  * Method reference expressions introduced in Java 8 specifically designed to simplify lambda Expressions.
@@ -83,10 +84,11 @@ public class MethodReferenceExpr extends Expression implements NodeWithTypeArgum
         return scope;
     }
 
-    public MethodReferenceExpr setScope(Expression scope) {
+    public MethodReferenceExpr setScope(final Expression scope) {
+        assertNotNull(scope);
         notifyPropertyChange(ObservableProperty.SCOPE, this.scope, scope);
         this.scope = scope;
-        setAsParentNodeOf(this.scope);
+        setAsParentNodeOf(scope);
         return this;
     }
 
@@ -103,9 +105,9 @@ public class MethodReferenceExpr extends Expression implements NodeWithTypeArgum
      */
     @Override
     public MethodReferenceExpr setTypeArguments(final NodeList<Type> typeArguments) {
-        notifyPropertyChange(ObservableProperty.TYPE, this.typeArguments, typeArguments);
+        notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
         this.typeArguments = typeArguments;
-        setAsParentNodeOf(this.typeArguments);
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
@@ -115,7 +117,7 @@ public class MethodReferenceExpr extends Expression implements NodeWithTypeArgum
     }
 
     @Override
-    public MethodReferenceExpr setIdentifier(String identifier) {
+    public MethodReferenceExpr setIdentifier(final String identifier) {
         assertNonEmpty(identifier);
         notifyPropertyChange(ObservableProperty.IDENTIFIER, this.identifier, identifier);
         this.identifier = identifier;
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NameExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NameExpr.java
index aa57da6cb..1d896e74a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NameExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NameExpr.java
@@ -73,8 +73,9 @@ public class NameExpr extends Expression implements NodeWithSimpleName<NameExpr>
 
     @Override
     public NameExpr setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NormalAnnotationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NormalAnnotationExpr.java
index a466a46cd..d55809032 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NormalAnnotationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/NormalAnnotationExpr.java
@@ -67,9 +67,10 @@ public final class NormalAnnotationExpr extends AnnotationExpr {
     }
 
     public NormalAnnotationExpr setPairs(final NodeList<MemberValuePair> pairs) {
+        assertNotNull(pairs);
         notifyPropertyChange(ObservableProperty.PAIRS, this.pairs, pairs);
-        this.pairs = assertNotNull(pairs);
-        setAsParentNodeOf(this.pairs);
+        this.pairs = pairs;
+        setAsParentNodeOf(pairs);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ObjectCreationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ObjectCreationExpr.java
index 4ee8956fc..566e44a61 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ObjectCreationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ObjectCreationExpr.java
@@ -132,15 +132,16 @@ public final class ObjectCreationExpr extends Expression implements NodeWithType
     public ObjectCreationExpr setAnonymousClassBody(final NodeList<BodyDeclaration<?>> anonymousClassBody) {
         notifyPropertyChange(ObservableProperty.ANONYMOUS_CLASS_BODY, this.anonymousClassBody, anonymousClassBody);
         this.anonymousClassBody = anonymousClassBody;
-        setAsParentNodeOf(this.anonymousClassBody);
+        setAsParentNodeOf(anonymousClassBody);
         return this;
     }
 
     @Override
     public ObjectCreationExpr setArguments(final NodeList<Expression> arguments) {
+        assertNotNull(arguments);
         notifyPropertyChange(ObservableProperty.ARGUMENTS, this.arguments, arguments);
-        this.arguments = assertNotNull(arguments);
-        setAsParentNodeOf(this.arguments);
+        this.arguments = arguments;
+        setAsParentNodeOf(arguments);
         return this;
     }
 
@@ -154,16 +155,16 @@ public final class ObjectCreationExpr extends Expression implements NodeWithType
     public ObjectCreationExpr setScope(final Expression scope) {
         notifyPropertyChange(ObservableProperty.SCOPE, this.scope, scope);
         this.scope = scope;
-        setAsParentNodeOf(this.scope);
+        setAsParentNodeOf(scope);
         return this;
     }
 
     @Override
     public ObjectCreationExpr setType(final ClassOrInterfaceType type) {
-        notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         assertNotNull(type);
+        notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
-        setAsParentNodeOf(this.type);
+        setAsParentNodeOf(type);
         return this;
     }
 
@@ -182,7 +183,7 @@ public final class ObjectCreationExpr extends Expression implements NodeWithType
     public ObjectCreationExpr setTypeArguments(final NodeList<Type> typeArguments) {
         notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
         this.typeArguments = typeArguments;
-        setAsParentNodeOf(this.typeArguments);
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SingleMemberAnnotationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SingleMemberAnnotationExpr.java
index d0c30d3f2..33ac01e38 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SingleMemberAnnotationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SingleMemberAnnotationExpr.java
@@ -26,6 +26,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * An annotation that has a single value. <br/><code>@Count(15)</code>
  *
@@ -64,9 +66,10 @@ public final class SingleMemberAnnotationExpr extends AnnotationExpr {
     }
 
     public SingleMemberAnnotationExpr setMemberValue(final Expression memberValue) {
+        assertNotNull(memberValue);
         notifyPropertyChange(ObservableProperty.MEMBER_VALUE, this.memberValue, memberValue);
         this.memberValue = memberValue;
-        setAsParentNodeOf(this.memberValue);
+        setAsParentNodeOf(memberValue);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/StringLiteralExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/StringLiteralExpr.java
index f1e067037..bc323251a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/StringLiteralExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/StringLiteralExpr.java
@@ -77,11 +77,9 @@ public class StringLiteralExpr extends LiteralExpr {
     }
 
     public final StringLiteralExpr setValue(final String value) {
+        assertNotNull(value);
         notifyPropertyChange(ObservableProperty.VALUE, this.value, value);
-        this.value = assertNotNull(value);
-        if (value.contains("\n") || value.contains("\r")) {
-            throw new IllegalArgumentException("Illegal literal expression: newlines (line feed or carriage return) have to be escaped");
-        }
+        this.value = value;
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SuperExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SuperExpr.java
index 056eaa6a2..c24dbb71f 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SuperExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/SuperExpr.java
@@ -77,7 +77,7 @@ public final class SuperExpr extends Expression {
     public SuperExpr setClassExpr(final Expression classExpr) {
         notifyPropertyChange(ObservableProperty.CLASS_EXPR, this.classExpr, classExpr);
         this.classExpr = classExpr;
-        setAsParentNodeOf(this.classExpr);
+        setAsParentNodeOf(classExpr);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ThisExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ThisExpr.java
index 3d29c752d..8cf273761 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ThisExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/ThisExpr.java
@@ -71,7 +71,7 @@ public final class ThisExpr extends Expression {
     public ThisExpr setClassExpr(final Expression classExpr) {
         notifyPropertyChange(ObservableProperty.CLASS_EXPR, this.classExpr, classExpr);
         this.classExpr = classExpr;
-        setAsParentNodeOf(this.classExpr);
+        setAsParentNodeOf(classExpr);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/TypeExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/TypeExpr.java
index 35c927df2..4ae8e34bc 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/TypeExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/TypeExpr.java
@@ -71,10 +71,11 @@ public class TypeExpr extends Expression implements NodeWithType<TypeExpr, Type>
     }
 
     @Override
-    public TypeExpr setType(Type type) {
+    public TypeExpr setType(final Type type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
-        this.type = assertNotNull(type);
-        setAsParentNodeOf(this.type);
+        this.type = type;
+        setAsParentNodeOf(type);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/UnaryExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/UnaryExpr.java
index 77264e9a8..836d6e22a 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/UnaryExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/UnaryExpr.java
@@ -27,6 +27,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * An expression where an operator is applied to a single expression.
  * It supports the operators that are found the the UnaryExpr.Operator enum.
@@ -104,16 +106,18 @@ public final class UnaryExpr extends Expression implements NodeWithExpression<Un
     }
 
     @Override
-    public UnaryExpr setExpression(final Expression expr) {
-        notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expr);
-        this.expression = expr;
-        setAsParentNodeOf(this.expression);
+    public UnaryExpr setExpression(final Expression expression) {
+        assertNotNull(expression);
+        notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
+        this.expression = expression;
+        setAsParentNodeOf(expression);
         return this;
     }
 
-    public UnaryExpr setOperator(final Operator op) {
-        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, op);
-        this.operator = op;
+    public UnaryExpr setOperator(final Operator operator) {
+        assertNotNull(operator);
+        notifyPropertyChange(ObservableProperty.OPERATOR, this.operator, operator);
+        this.operator = operator;
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/VariableDeclarationExpr.java b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/VariableDeclarationExpr.java
index 29c746385..b3108ca2b 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/expr/VariableDeclarationExpr.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/expr/VariableDeclarationExpr.java
@@ -128,14 +128,16 @@ public final class VariableDeclarationExpr extends Expression implements NodeWit
 
     @Override
     public VariableDeclarationExpr setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
-        this.annotations = assertNotNull(annotations);
-        setAsParentNodeOf(this.annotations);
+        this.annotations = annotations;
+        setAsParentNodeOf(annotations);
         return this;
     }
 
     @Override
     public VariableDeclarationExpr setModifiers(final EnumSet<Modifier> modifiers) {
+        assertNotNull(modifiers);
         notifyPropertyChange(ObservableProperty.MODIFIERS, this.modifiers, modifiers);
         this.modifiers = modifiers;
         return this;
@@ -143,9 +145,10 @@ public final class VariableDeclarationExpr extends Expression implements NodeWit
 
     @Override
     public VariableDeclarationExpr setVariables(final NodeList<VariableDeclarator> variables) {
+        assertNotNull(variables);
         notifyPropertyChange(ObservableProperty.VARIABLES, this.variables, variables);
         this.variables = variables;
-        setAsParentNodeOf(this.variables);
+        setAsParentNodeOf(variables);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/observer/ObservableProperty.java b/javaparser-core/src/main/java/com/github/javaparser/ast/observer/ObservableProperty.java
index f1f72a4d4..08a914058 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/observer/ObservableProperty.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/observer/ObservableProperty.java
@@ -18,89 +18,13 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
  */
-
 package com.github.javaparser.ast.observer;
 
 /**
  * Properties considered by the AstObserver
  */
 public enum ObservableProperty {
-    ANNOTATIONS,
-    ANONYMOUS_CLASS_BODY,
-    ARGUMENTS,
-    BLOCK,
-    BODY,
-    CATCH_CLAUSES,
-    CHECK,
-    CLASS_BODY,
-    CLASS_EXPR,
-    COMMENT,
-    COMMENTED_NODE,
-    COMPARE,
-    COMPONENT_TYPE,
-    CONDITION,
-    CONTENT,
-    DEFAULT_VALUE,
-    DIMENSION,
-    ELEMENTS,
-    ELSE_EXPR,
-    ELSE_STMT,
-    ENTRIES,
-    EXPRESSION,
-    EXTENDED_TYPES,
-    FIELD,
-    FINALLY_BLOCK,
-    IDENTIFIER,
-    IMPLEMENTED_TYPES,
-    IMPORTS,
-    INDEX,
-    INITIALIZER,
-    INNER,
-    IS_INTERFACE,
-    ITERABLE,
-    IS_THIS,
-    LABEL,
-    LEFT,
-    LEVELS,
-    MEMBERS,
-    MEMBER_VALUE,
-    MODIFIERS,
-    MESSAGE,
-    NAME,
-    OPERATOR,
-    PACKAGE_DECLARATION,
-    PAIRS,
-    PARAMETER,
-    PARAMETERS,
-    ENCLOSING_PARAMETERS,
-    QUALIFIER,
-    RANGE,
-    RESOURCES,
-    RIGHT,
-    SCOPE,
-    SELECTOR,
-    IS_ASTERISK,
-    IS_STATIC,
-    STATIC_MEMBER,
-    STATEMENT,
-    STATEMENTS,
-    SUPER,
-    TARGET,
-    THEN_EXPR,
-    THEN_STMT,
-    THROWN_TYPES,
-    TRY_BLOCK,
-    TYPE,
-    TYPES,
-    TYPE_ARGUMENTS,
-    TYPE_BOUND,
-    CLASS_DECLARATION,
-    TYPE_PARAMETERS,
-    UPDATE,
-    VALUE,
-    VALUES,
-    VARIABLE,
-    VARIABLES,
-    ELEMENT_TYPE,
-    VAR_ARGS
+
+    ANNOTATIONS, ANONYMOUS_CLASS_BODY, ARGUMENTS, ASTERISK, BODY, CATCH_CLAUSES, CHECK, CLASS_BODY, CLASS_DECLARATION, CLASS_EXPR, COMMENT, COMPARE, COMPONENT_TYPE, CONDITION, CONTENT, DEFAULT, DEFAULT_VALUE, DIMENSION, ELEMENTS, ELEMENT_TYPE, ELSE_EXPR, ELSE_STMT, ENCLOSING_PARAMETERS, ENTRIES, EXPRESSION, EXTENDED_TYPES, FINALLY_BLOCK, IDENTIFIER, IMPLEMENTED_TYPES, IMPORTS, INDEX, INITIALIZATION, INITIALIZER, INNER, INTERFACE, ITERABLE, LABEL, LEFT, LEVELS, MEMBERS, MEMBER_VALUE, MESSAGE, MODIFIERS, NAME, OPERATOR, PACKAGE_DECLARATION, PAIRS, PARAMETER, PARAMETERS, QUALIFIER, RESOURCES, RIGHT, SCOPE, SELECTOR, STATEMENT, STATEMENTS, STATIC, SUPER_TYPES, TARGET, THEN_EXPR, THEN_STMT, THIS, THROWN_EXCEPTIONS, TRY_BLOCK, TYPE, TYPES, TYPE_ARGUMENTS, TYPE_BOUND, TYPE_PARAMETERS, UPDATE, VALUE, VALUES, VARIABLE, VARIABLES, VAR_ARGS, RANGE, COMMENTED_NODE
 }
+
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/AssertStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/AssertStmt.java
index 8f7cbcd0e..9758c06a4 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/AssertStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/AssertStmt.java
@@ -79,9 +79,10 @@ public final class AssertStmt extends Statement {
     }
 
     public AssertStmt setCheck(final Expression check) {
+        assertNotNull(check);
         notifyPropertyChange(ObservableProperty.CHECK, this.check, check);
-        this.check = assertNotNull(check);
-        setAsParentNodeOf(this.check);
+        this.check = check;
+        setAsParentNodeOf(check);
         return this;
     }
 
@@ -91,10 +92,10 @@ public final class AssertStmt extends Statement {
      * @param msg the message, can be null
      * @return this, the AssertStmt
      */
-    public AssertStmt setMessage(final Expression msg) {
-        notifyPropertyChange(ObservableProperty.MESSAGE, this.message, msg);
-        this.message = msg;
-        setAsParentNodeOf(this.message);
+    public AssertStmt setMessage(final Expression message) {
+        notifyPropertyChange(ObservableProperty.MESSAGE, this.message, message);
+        this.message = message;
+        setAsParentNodeOf(message);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BlockStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BlockStmt.java
index c837defea..ed8cafd02 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BlockStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BlockStmt.java
@@ -69,9 +69,10 @@ public final class BlockStmt extends Statement implements NodeWithStatements<Blo
     }
 
     public BlockStmt setStatements(final NodeList<Statement> statements) {
+        assertNotNull(statements);
         notifyPropertyChange(ObservableProperty.STATEMENTS, this.statements, statements);
-        this.statements = assertNotNull(statements);
-        setAsParentNodeOf(this.statements);
+        this.statements = statements;
+        setAsParentNodeOf(statements);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BreakStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BreakStmt.java
index f974393ff..5b45126e4 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BreakStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/BreakStmt.java
@@ -79,7 +79,8 @@ public final class BreakStmt extends Statement {
      */
     public BreakStmt setLabel(final SimpleName label) {
         notifyPropertyChange(ObservableProperty.LABEL, this.label, label);
-        this.label = assertNotNull(label);
+        this.label = label;
+        setAsParentNodeOf(label);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/CatchClause.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/CatchClause.java
index 970836641..6a3115631 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/CatchClause.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/CatchClause.java
@@ -35,6 +35,8 @@ import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 import java.util.EnumSet;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * The catch part of a try-catch-finally. <br/>In <code>try { ... } catch (Exception e) { ... }</code> the CatchClause
  * is <code>catch (Exception e) { ... }</code>. Exception e is the parameter. The { ... } is the body.
@@ -86,9 +88,10 @@ public final class CatchClause extends Node implements NodeWithBlockStmt<CatchCl
     }
 
     public CatchClause setParameter(final Parameter parameter) {
+        assertNotNull(parameter);
         notifyPropertyChange(ObservableProperty.PARAMETER, this.parameter, parameter);
         this.parameter = parameter;
-        setAsParentNodeOf(this.parameter);
+        setAsParentNodeOf(parameter);
         return this;
     }
 
@@ -98,10 +101,11 @@ public final class CatchClause extends Node implements NodeWithBlockStmt<CatchCl
     }
 
     @Override
-    public CatchClause setBody(BlockStmt block) {
-        notifyPropertyChange(ObservableProperty.BODY, this.body, block);
-        this.body = block;
-        setAsParentNodeOf(this.body);
+    public CatchClause setBody(final BlockStmt body) {
+        assertNotNull(body);
+        notifyPropertyChange(ObservableProperty.BODY, this.body, body);
+        this.body = body;
+        setAsParentNodeOf(body);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ContinueStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ContinueStmt.java
index 464bc7217..48c4210ba 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ContinueStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ContinueStmt.java
@@ -83,7 +83,8 @@ public final class ContinueStmt extends Statement implements NodeWithOptionalLab
     @Override
     public ContinueStmt setLabel(final SimpleName label) {
         notifyPropertyChange(ObservableProperty.LABEL, this.label, label);
-        this.label = assertNotNull(label);
+        this.label = label;
+        setAsParentNodeOf(label);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/DoStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/DoStmt.java
index 7656565a2..6d16d0f5d 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/DoStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/DoStmt.java
@@ -29,6 +29,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * A do-while.
  * <br/><code>do { ... } while ( a==0 );</code>
@@ -77,16 +79,18 @@ public final class DoStmt extends Statement implements NodeWithBody<DoStmt> {
 
     @Override
     public DoStmt setBody(final Statement body) {
+        assertNotNull(body);
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
         this.body = body;
-        setAsParentNodeOf(this.body);
+        setAsParentNodeOf(body);
         return this;
     }
 
     public DoStmt setCondition(final Expression condition) {
+        assertNotNull(condition);
         notifyPropertyChange(ObservableProperty.CONDITION, this.condition, condition);
         this.condition = condition;
-        setAsParentNodeOf(this.condition);
+        setAsParentNodeOf(condition);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExplicitConstructorInvocationStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExplicitConstructorInvocationStmt.java
index f6733ab1e..c208936b4 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExplicitConstructorInvocationStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExplicitConstructorInvocationStmt.java
@@ -111,9 +111,10 @@ public final class ExplicitConstructorInvocationStmt extends Statement implement
     }
 
     public ExplicitConstructorInvocationStmt setArguments(final NodeList<Expression> arguments) {
+        assertNotNull(arguments);
         notifyPropertyChange(ObservableProperty.ARGUMENTS, this.arguments, arguments);
-        this.arguments = assertNotNull(arguments);
-        setAsParentNodeOf(this.arguments);
+        this.arguments = arguments;
+        setAsParentNodeOf(arguments);
         return this;
     }
 
@@ -126,12 +127,12 @@ public final class ExplicitConstructorInvocationStmt extends Statement implement
     public ExplicitConstructorInvocationStmt setExpression(final Expression expression) {
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
         this.expression = expression;
-        setAsParentNodeOf(this.expression);
+        setAsParentNodeOf(expression);
         return this;
     }
 
     public ExplicitConstructorInvocationStmt setThis(final boolean isThis) {
-        notifyPropertyChange(ObservableProperty.IS_THIS, this.isThis, isThis);
+        notifyPropertyChange(ObservableProperty.THIS, this.isThis, isThis);
         this.isThis = isThis;
         return this;
     }
@@ -151,7 +152,7 @@ public final class ExplicitConstructorInvocationStmt extends Statement implement
     public ExplicitConstructorInvocationStmt setTypeArguments(final NodeList<Type> typeArguments) {
         notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
         this.typeArguments = typeArguments;
-        setAsParentNodeOf(this.typeArguments);
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExpressionStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExpressionStmt.java
index 094f78a24..88549adce 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExpressionStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ExpressionStmt.java
@@ -70,9 +70,10 @@ public final class ExpressionStmt extends Statement implements NodeWithExpressio
 
     @Override
     public ExpressionStmt setExpression(final Expression expression) {
+        assertNotNull(expression);
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
-        this.expression = assertNotNull(expression);
-        setAsParentNodeOf(this.expression);
+        this.expression = expression;
+        setAsParentNodeOf(expression);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForStmt.java
index 0dea6a494..fcbd46c01 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForStmt.java
@@ -97,9 +97,10 @@ public final class ForStmt extends Statement implements NodeWithBody<ForStmt> {
 
     @Override
     public ForStmt setBody(final Statement body) {
+        assertNotNull(body);
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
         this.body = body;
-        setAsParentNodeOf(this.body);
+        setAsParentNodeOf(body);
         return this;
     }
 
@@ -112,21 +113,23 @@ public final class ForStmt extends Statement implements NodeWithBody<ForStmt> {
     public ForStmt setCompare(final Expression compare) {
         notifyPropertyChange(ObservableProperty.COMPARE, this.compare, compare);
         this.compare = compare;
-        setAsParentNodeOf(this.compare);
+        setAsParentNodeOf(compare);
         return this;
     }
 
     public ForStmt setInitialization(final NodeList<Expression> initialization) {
-        notifyPropertyChange(ObservableProperty.INITIALIZER, this.initialization, initialization);
-        this.initialization = assertNotNull(initialization);
-        setAsParentNodeOf(this.initialization);
+        assertNotNull(initialization);
+        notifyPropertyChange(ObservableProperty.INITIALIZATION, this.initialization, initialization);
+        this.initialization = initialization;
+        setAsParentNodeOf(initialization);
         return this;
     }
 
     public ForStmt setUpdate(final NodeList<Expression> update) {
+        assertNotNull(update);
         notifyPropertyChange(ObservableProperty.UPDATE, this.update, update);
-        this.update = assertNotNull(update);
-        setAsParentNodeOf(this.update);
+        this.update = update;
+        setAsParentNodeOf(update);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForeachStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForeachStmt.java
index 4075de63a..eb55820ce 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForeachStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ForeachStmt.java
@@ -90,23 +90,26 @@ public final class ForeachStmt extends Statement implements NodeWithBody<Foreach
 
     @Override
     public ForeachStmt setBody(final Statement body) {
+        assertNotNull(body);
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
-        this.body = assertNotNull(body);
-        setAsParentNodeOf(this.body);
+        this.body = body;
+        setAsParentNodeOf(body);
         return this;
     }
 
     public ForeachStmt setIterable(final Expression iterable) {
+        assertNotNull(iterable);
         notifyPropertyChange(ObservableProperty.ITERABLE, this.iterable, iterable);
-        this.iterable = assertNotNull(iterable);
-        setAsParentNodeOf(this.iterable);
+        this.iterable = iterable;
+        setAsParentNodeOf(iterable);
         return this;
     }
 
-    public ForeachStmt setVariable(final VariableDeclarationExpr var) {
-        notifyPropertyChange(ObservableProperty.VARIABLE, this.variable, var);
-        this.variable = assertNotNull(var);
-        setAsParentNodeOf(this.variable);
+    public ForeachStmt setVariable(final VariableDeclarationExpr variable) {
+        assertNotNull(variable);
+        notifyPropertyChange(ObservableProperty.VARIABLE, this.variable, variable);
+        this.variable = variable;
+        setAsParentNodeOf(variable);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/IfStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/IfStmt.java
index b4604cc09..6ad14fd43 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/IfStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/IfStmt.java
@@ -84,9 +84,10 @@ public final class IfStmt extends Statement {
     }
 
     public IfStmt setCondition(final Expression condition) {
+        assertNotNull(condition);
         notifyPropertyChange(ObservableProperty.CONDITION, this.condition, condition);
-        this.condition = assertNotNull(condition);
-        setAsParentNodeOf(this.condition);
+        this.condition = condition;
+        setAsParentNodeOf(condition);
         return this;
     }
 
@@ -99,14 +100,15 @@ public final class IfStmt extends Statement {
     public IfStmt setElseStmt(final Statement elseStmt) {
         notifyPropertyChange(ObservableProperty.ELSE_STMT, this.elseStmt, elseStmt);
         this.elseStmt = elseStmt;
-        setAsParentNodeOf(this.elseStmt);
+        setAsParentNodeOf(elseStmt);
         return this;
     }
 
     public IfStmt setThenStmt(final Statement thenStmt) {
+        assertNotNull(thenStmt);
         notifyPropertyChange(ObservableProperty.THEN_STMT, this.thenStmt, thenStmt);
-        this.thenStmt = assertNotNull(thenStmt);
-        setAsParentNodeOf(this.thenStmt);
+        this.thenStmt = thenStmt;
+        setAsParentNodeOf(thenStmt);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LabeledStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LabeledStmt.java
index bfcfdc302..6686bfac9 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LabeledStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LabeledStmt.java
@@ -73,9 +73,10 @@ public final class LabeledStmt extends Statement {
     }
 
     public LabeledStmt setStatement(final Statement statement) {
+        assertNotNull(statement);
         notifyPropertyChange(ObservableProperty.STATEMENT, this.statement, statement);
-        this.statement = assertNotNull(statement);
-        setAsParentNodeOf(this.statement);
+        this.statement = statement;
+        setAsParentNodeOf(statement);
         return this;
     }
 
@@ -84,8 +85,9 @@ public final class LabeledStmt extends Statement {
     }
 
     public LabeledStmt setLabel(final SimpleName label) {
+        assertNotNull(label);
         notifyPropertyChange(ObservableProperty.LABEL, this.label, label);
-        this.label = assertNotNull(label);
+        this.label = label;
         setAsParentNodeOf(label);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LocalClassDeclarationStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LocalClassDeclarationStmt.java
index 4513d8bd6..509ddc1ae 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LocalClassDeclarationStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/LocalClassDeclarationStmt.java
@@ -70,9 +70,10 @@ public final class LocalClassDeclarationStmt extends Statement {
     }
 
     public LocalClassDeclarationStmt setClassDeclaration(final ClassOrInterfaceDeclaration classDeclaration) {
+        assertNotNull(classDeclaration);
         notifyPropertyChange(ObservableProperty.CLASS_DECLARATION, this.classDeclaration, classDeclaration);
-        this.classDeclaration = assertNotNull(classDeclaration);
-        setAsParentNodeOf(this.classDeclaration);
+        this.classDeclaration = classDeclaration;
+        setAsParentNodeOf(classDeclaration);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ReturnStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ReturnStmt.java
index 467badb0f..d0cc86c30 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ReturnStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ReturnStmt.java
@@ -82,7 +82,7 @@ public final class ReturnStmt extends Statement {
     public ReturnStmt setExpression(final Expression expression) {
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
         this.expression = expression;
-        setAsParentNodeOf(this.expression);
+        setAsParentNodeOf(expression);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchEntryStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchEntryStmt.java
index 73845672b..d47d86e1d 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchEntryStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchEntryStmt.java
@@ -101,14 +101,15 @@ public final class SwitchEntryStmt extends Statement implements NodeWithStatemen
     public SwitchEntryStmt setLabel(final Expression label) {
         notifyPropertyChange(ObservableProperty.LABEL, this.label, label);
         this.label = label;
-        setAsParentNodeOf(this.label);
+        setAsParentNodeOf(label);
         return this;
     }
 
     public SwitchEntryStmt setStatements(final NodeList<Statement> statements) {
+        assertNotNull(statements);
         notifyPropertyChange(ObservableProperty.STATEMENTS, this.statements, statements);
-        this.statements = assertNotNull(statements);
-        setAsParentNodeOf(this.statements);
+        this.statements = statements;
+        setAsParentNodeOf(statements);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchStmt.java
index c91f5b995..dd481eb2c 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SwitchStmt.java
@@ -84,9 +84,10 @@ public final class SwitchStmt extends Statement {
     }
 
     public SwitchStmt setEntries(final NodeList<SwitchEntryStmt> entries) {
+        assertNotNull(entries);
         notifyPropertyChange(ObservableProperty.ENTRIES, this.entries, entries);
-        this.entries = assertNotNull(entries);
-        setAsParentNodeOf(this.entries);
+        this.entries = entries;
+        setAsParentNodeOf(entries);
         return this;
     }
 
@@ -101,9 +102,10 @@ public final class SwitchStmt extends Statement {
     }
 
     public SwitchStmt setSelector(final Expression selector) {
+        assertNotNull(selector);
         notifyPropertyChange(ObservableProperty.SELECTOR, this.selector, selector);
         this.selector = selector;
-        setAsParentNodeOf(this.selector);
+        setAsParentNodeOf(selector);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SynchronizedStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SynchronizedStmt.java
index cd67b2737..8ddaac077 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SynchronizedStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/SynchronizedStmt.java
@@ -73,9 +73,10 @@ public final class SynchronizedStmt extends Statement implements NodeWithBlockSt
     }
 
     public SynchronizedStmt setExpression(final Expression expression) {
+        assertNotNull(expression);
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
-        this.expression = assertNotNull(expression);
-        setAsParentNodeOf(this.expression);
+        this.expression = expression;
+        setAsParentNodeOf(expression);
         return this;
     }
 
@@ -85,10 +86,11 @@ public final class SynchronizedStmt extends Statement implements NodeWithBlockSt
     }
 
     @Override
-    public SynchronizedStmt setBody(BlockStmt body) {
+    public SynchronizedStmt setBody(final BlockStmt body) {
+        assertNotNull(body);
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
-        this.body = assertNotNull(body);
-        setAsParentNodeOf(this.body);
+        this.body = body;
+        setAsParentNodeOf(body);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ThrowStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ThrowStmt.java
index 7d0079744..b983a7896 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ThrowStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/ThrowStmt.java
@@ -29,6 +29,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * Usage of the throw statement.
  * <br/><code>throw new Exception()</code>
@@ -70,9 +72,10 @@ public final class ThrowStmt extends Statement implements NodeWithExpression<Thr
 
     @Override
     public ThrowStmt setExpression(final Expression expression) {
+        assertNotNull(expression);
         notifyPropertyChange(ObservableProperty.EXPRESSION, this.expression, expression);
         this.expression = expression;
-        setAsParentNodeOf(this.expression);
+        setAsParentNodeOf(expression);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/TryStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/TryStmt.java
index 02e4cf798..264b5da0e 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/TryStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/TryStmt.java
@@ -108,30 +108,32 @@ public final class TryStmt extends Statement {
     }
 
     public TryStmt setCatchClauses(final NodeList<CatchClause> catchClauses) {
+        assertNotNull(catchClauses);
         notifyPropertyChange(ObservableProperty.CATCH_CLAUSES, this.catchClauses, catchClauses);
-        this.catchClauses = assertNotNull(catchClauses);
-        setAsParentNodeOf(this.catchClauses);
+        this.catchClauses = catchClauses;
+        setAsParentNodeOf(catchClauses);
         return this;
     }
 
     public TryStmt setFinallyBlock(final BlockStmt finallyBlock) {
         notifyPropertyChange(ObservableProperty.FINALLY_BLOCK, this.finallyBlock, finallyBlock);
         this.finallyBlock = finallyBlock;
-        setAsParentNodeOf(this.finallyBlock);
+        setAsParentNodeOf(finallyBlock);
         return this;
     }
 
     public TryStmt setTryBlock(final BlockStmt tryBlock) {
         notifyPropertyChange(ObservableProperty.TRY_BLOCK, this.tryBlock, tryBlock);
         this.tryBlock = tryBlock;
-        setAsParentNodeOf(this.tryBlock);
+        setAsParentNodeOf(tryBlock);
         return this;
     }
 
-    public TryStmt setResources(NodeList<VariableDeclarationExpr> resources) {
+    public TryStmt setResources(final NodeList<VariableDeclarationExpr> resources) {
+        assertNotNull(resources);
         notifyPropertyChange(ObservableProperty.RESOURCES, this.resources, resources);
-        this.resources = assertNotNull(resources);
-        setAsParentNodeOf(this.resources);
+        this.resources = resources;
+        setAsParentNodeOf(resources);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/WhileStmt.java b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/WhileStmt.java
index 9ea77b066..883794e7c 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/WhileStmt.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/stmt/WhileStmt.java
@@ -29,6 +29,8 @@ import com.github.javaparser.ast.observer.ObservableProperty;
 import com.github.javaparser.ast.visitor.GenericVisitor;
 import com.github.javaparser.ast.visitor.VoidVisitor;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * A while statement.
  * <br/><code>while(true) { ... }</code>
@@ -77,16 +79,18 @@ public final class WhileStmt extends Statement implements NodeWithBody<WhileStmt
 
     @Override
     public WhileStmt setBody(final Statement body) {
+        assertNotNull(body);
         notifyPropertyChange(ObservableProperty.BODY, this.body, body);
         this.body = body;
-        setAsParentNodeOf(this.body);
+        setAsParentNodeOf(body);
         return this;
     }
 
     public WhileStmt setCondition(final Expression condition) {
+        assertNotNull(condition);
         notifyPropertyChange(ObservableProperty.CONDITION, this.condition, condition);
         this.condition = condition;
-        setAsParentNodeOf(this.condition);
+        setAsParentNodeOf(condition);
         return this;
     }
 }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/ArrayType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/ArrayType.java
index bb14c8b5a..77b66f1c7 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/ArrayType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/ArrayType.java
@@ -73,10 +73,11 @@ public class ArrayType extends ReferenceType implements NodeWithAnnotations<Arra
         return componentType;
     }
 
-    public ArrayType setComponentType(final Type type) {
+    public ArrayType setComponentType(final Type componentType) {
+        assertNotNull(componentType);
         notifyPropertyChange(ObservableProperty.COMPONENT_TYPE, this.componentType, componentType);
-        this.componentType = assertNotNull(type);
-        setAsParentNodeOf(this.componentType);
+        this.componentType = componentType;
+        setAsParentNodeOf(componentType);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/ClassOrInterfaceType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/ClassOrInterfaceType.java
index a8a30f204..e882ae2e7 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/ClassOrInterfaceType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/ClassOrInterfaceType.java
@@ -112,8 +112,9 @@ public final class ClassOrInterfaceType extends ReferenceType implements NodeWit
 
     @Override
     public ClassOrInterfaceType setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
@@ -125,9 +126,9 @@ public final class ClassOrInterfaceType extends ReferenceType implements NodeWit
      * @return this, the ClassOrInterfaceType
      */
     public ClassOrInterfaceType setScope(final ClassOrInterfaceType scope) {
-        notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
+        notifyPropertyChange(ObservableProperty.SCOPE, this.scope, scope);
         this.scope = scope;
-        setAsParentNodeOf(this.scope);
+        setAsParentNodeOf(scope);
         return this;
     }
 
@@ -146,7 +147,7 @@ public final class ClassOrInterfaceType extends ReferenceType implements NodeWit
     public ClassOrInterfaceType setTypeArguments(final NodeList<Type> typeArguments) {
         notifyPropertyChange(ObservableProperty.TYPE_ARGUMENTS, this.typeArguments, typeArguments);
         this.typeArguments = typeArguments;
-        setAsParentNodeOf(this.typeArguments);
+        setAsParentNodeOf(typeArguments);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/IntersectionType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/IntersectionType.java
index e2e17ec2e..a04fcef5c 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/IntersectionType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/IntersectionType.java
@@ -72,10 +72,11 @@ public class IntersectionType extends Type implements NodeWithAnnotations<Inters
         return elements;
     }
 
-    public IntersectionType setElements(NodeList<ReferenceType> elements) {
+    public IntersectionType setElements(final NodeList<ReferenceType> elements) {
+        assertNotNull(elements);
         notifyPropertyChange(ObservableProperty.ELEMENTS, this.elements, elements);
-        this.elements = assertNotNull(elements);
-        setAsParentNodeOf(this.elements);
+        this.elements = elements;
+        setAsParentNodeOf(elements);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/PrimitiveType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/PrimitiveType.java
index 00fe28ee3..0ec8ad490 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/PrimitiveType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/PrimitiveType.java
@@ -32,6 +32,8 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 
+import static com.github.javaparser.utils.Utils.assertNotNull;
+
 /**
  * A primitive type.
  * <br/><code>int</code>
@@ -139,6 +141,7 @@ public final class PrimitiveType extends Type implements NodeWithAnnotations<Pri
     }
 
     public PrimitiveType setType(final Primitive type) {
+        assertNotNull(type);
         notifyPropertyChange(ObservableProperty.TYPE, this.type, type);
         this.type = type;
         return this;
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/Type.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/Type.java
index 88de15374..5963421ea 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/Type.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/Type.java
@@ -49,9 +49,10 @@ public abstract class Type extends Node {
         return getAnnotations().get(i);
     }
 
-    public Type setAnnotations(NodeList<AnnotationExpr> annotations) {
+    public Type setAnnotations(final NodeList<AnnotationExpr> annotations) {
+        assertNotNull(annotations);
         notifyPropertyChange(ObservableProperty.ANNOTATIONS, this.annotations, annotations);
-        this.annotations = assertNotNull(annotations);
+        this.annotations = annotations;
         setAsParentNodeOf(annotations);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/TypeParameter.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/TypeParameter.java
index bb0894ca2..cbbe78f7b 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/TypeParameter.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/TypeParameter.java
@@ -112,15 +112,17 @@ public final class TypeParameter extends ReferenceType<TypeParameter> implements
 
     @Override
     public TypeParameter setName(final SimpleName name) {
+        assertNotNull(name);
         notifyPropertyChange(ObservableProperty.NAME, this.name, name);
-        this.name = assertNotNull(name);
+        this.name = name;
         setAsParentNodeOf(name);
         return this;
     }
 
     public TypeParameter setTypeBound(final NodeList<ClassOrInterfaceType> typeBound) {
+        assertNotNull(typeBound);
         notifyPropertyChange(ObservableProperty.TYPE_BOUND, this.typeBound, typeBound);
-        this.typeBound = assertNotNull(typeBound);
+        this.typeBound = typeBound;
         setAsParentNodeOf(typeBound);
         return this;
     }
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/UnionType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/UnionType.java
index 09c666a20..d6b152ab6 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/UnionType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/UnionType.java
@@ -60,10 +60,11 @@ public class UnionType extends Type implements NodeWithAnnotations<UnionType> {
         return elements;
     }
 
-    public UnionType setElements(NodeList<ReferenceType> elements) {
+    public UnionType setElements(final NodeList<ReferenceType> elements) {
+        assertNotNull(elements);
         notifyPropertyChange(ObservableProperty.ELEMENTS, this.elements, elements);
-        this.elements = assertNotNull(elements);
-        setAsParentNodeOf(this.elements);
+        this.elements = elements;
+        setAsParentNodeOf(elements);
         return this;
     }
 
diff --git a/javaparser-core/src/main/java/com/github/javaparser/ast/type/WildcardType.java b/javaparser-core/src/main/java/com/github/javaparser/ast/type/WildcardType.java
index 84c6d9a1e..123f49c01 100644
--- a/javaparser-core/src/main/java/com/github/javaparser/ast/type/WildcardType.java
+++ b/javaparser-core/src/main/java/com/github/javaparser/ast/type/WildcardType.java
@@ -89,10 +89,10 @@ public final class WildcardType extends Type implements NodeWithAnnotations<Wild
      * @param ext the extends, can be null
      * @return this, the WildcardType
      */
-    public WildcardType setExtendedTypes(final ReferenceType ext) {
-        notifyPropertyChange(ObservableProperty.EXTENDED_TYPES, this.extendedTypes, ext);
-        this.extendedTypes = ext;
-        setAsParentNodeOf(this.extendedTypes);
+    public WildcardType setExtendedTypes(final ReferenceType extendedTypes) {
+        notifyPropertyChange(ObservableProperty.EXTENDED_TYPES, this.extendedTypes, extendedTypes);
+        this.extendedTypes = extendedTypes;
+        setAsParentNodeOf(extendedTypes);
         return this;
     }
 
@@ -102,10 +102,10 @@ public final class WildcardType extends Type implements NodeWithAnnotations<Wild
      * @param sup the super, can be null
      * @return this, the WildcardType
      */
-    public WildcardType setSuperTypes(final ReferenceType sup) {
-        notifyPropertyChange(ObservableProperty.SUPER, this.superTypes, sup);
-        this.superTypes = sup;
-        setAsParentNodeOf(this.superTypes);
+    public WildcardType setSuperTypes(final ReferenceType superTypes) {
+        notifyPropertyChange(ObservableProperty.SUPER_TYPES, this.superTypes, superTypes);
+        this.superTypes = superTypes;
+        setAsParentNodeOf(superTypes);
         return this;
     }