1 files changed, 14 insertions, 0 deletions
diff --git a/guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableSet.java b/guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableSet.java
index d5a8dad54..a5ba12333 100644
--- a/guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableSet.java
+++ b/guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableSet.java
@@ -18,6 +18,7 @@ package com.google.common.collect;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.concurrent.LazyInit;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -26,6 +27,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collector;
+import jsinterop.annotations.JsMethod;
 
 /**
  * GWT emulated version of {@link com.google.common.collect.ImmutableSet}. For the unsorted sets,
@@ -84,6 +86,13 @@ public abstract class ImmutableSet<E> extends ImmutableCollection<E> implements
     return copyOf(all.iterator());
   }
 
+  /** ImmutableSet.of API that is friendly to use from JavaScript. */
+  @JsMethod(name = "of")
+  static <E> ImmutableSet<E> jsOf(E... elements) {
+    return copyOf(elements);
+  }
+
+  @JsMethod
   public static <E> ImmutableSet<E> copyOf(E[] elements) {
     checkNotNull(elements);
     switch (elements.length) {
@@ -237,12 +246,14 @@ public abstract class ImmutableSet<E> extends ImmutableCollection<E> implements
       this.contents = Lists.newArrayListWithCapacity(initialCapacity);
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Builder<E> add(E element) {
       contents.add(checkNotNull(element));
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Builder<E> add(E... elements) {
       checkNotNull(elements); // for GWT
@@ -251,6 +262,7 @@ public abstract class ImmutableSet<E> extends ImmutableCollection<E> implements
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Builder<E> addAll(Iterable<? extends E> elements) {
       if (elements instanceof Collection) {
@@ -261,12 +273,14 @@ public abstract class ImmutableSet<E> extends ImmutableCollection<E> implements
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Builder<E> addAll(Iterator<? extends E> elements) {
       super.addAll(elements);
       return this;
     }
 
+    @CanIgnoreReturnValue
     Builder<E> combine(Builder<E> builder) {
       contents.addAll(builder.contents);
       return this;