[fixes #2682] Fix NPE, always add Javadoc return statement

test/transform/resource/after-ecj/WithMethodAbstract.java

@@ -3,5 +3,8 @@ abstract class WithMethodAbstract {
   WithMethodAbstract() {
     super();
   }
+  /**
+   * @return a clone of this object, except with this updated property (returns {@code this} if an identical value is passed).
+   */
   public abstract @java.lang.SuppressWarnings("all") WithMethodAbstract withFoo(final String foo);
 }