1 files changed, 23 insertions, 21 deletions
diff --git a/src/main/java/org/junit/rules/Verifier.java b/src/main/java/org/junit/rules/Verifier.java
index be1a55e..7a03b0c 100644
--- a/src/main/java/org/junit/rules/Verifier.java
+++ b/src/main/java/org/junit/rules/Verifier.java
@@ -7,39 +7,41 @@ import org.junit.runners.model.Statement;
  * Verifier is a base class for Rules like ErrorCollector, which can turn
  * otherwise passing test methods into failing tests if a verification check is
  * failed
- * 
+ *
  * <pre>
- *     public static class ErrorLogVerifier() {
+ *     public static class ErrorLogVerifier {
  *        private ErrorLog errorLog = new ErrorLog();
- *     
+ *
  *        &#064;Rule
- *        public MethodRule verifier = new Verifier() {
+ *        public Verifier verifier = new Verifier() {
  *           &#064;Override public void verify() {
  *              assertTrue(errorLog.isEmpty());
  *           }
  *        }
- *        
+ *
  *        &#064;Test public void testThatMightWriteErrorLog() {
  *           // ...
  *        }
  *     }
  * </pre>
+ *
+ * @since 4.7
  */
-public class Verifier implements TestRule {
-	public Statement apply(final Statement base, Description description) {
-		return new Statement() {
-			@Override
-			public void evaluate() throws Throwable {
-				base.evaluate();
-				verify();
-			}
-		};
-	}
+public abstract class Verifier implements TestRule {
+    public Statement apply(final Statement base, Description description) {
+        return new Statement() {
+            @Override
+            public void evaluate() throws Throwable {
+                base.evaluate();
+                verify();
+            }
+        };
+    }
 
-	/**
-	 * Override this to add verification logic. Overrides should throw an
-	 * exception to indicate that verification failed.
-	 */
-	protected void verify() throws Throwable {
-	}
+    /**
+     * Override this to add verification logic. Overrides should throw an
+     * exception to indicate that verification failed.
+     */
+    protected void verify() throws Throwable {
+    }
 }