src/share/classes/javax/lang/model/util/SimpleTypeVisitor6.java

@@ -116,10 +116,14 @@
 
     /**
      * The default action for visit methods.  The implementation in
      * this class just returns {@link #DEFAULT_VALUE}; subclasses will
      * commonly override this method.
+     *
+     * @param e the type to process
+     * @param p a visitor-specified parameter
+     * @return {@code DEFAULT_VALUE} unless overridden
      */
     protected R defaultAction(TypeMirror e, P p) {
         return DEFAULT_VALUE;
     }