code: private static boolean absentAnySetter(Method jsonAnyGetter, Method jsonAnySetter) {
          return (jsonAnySetter == null && jsonAnyGetter != null) ||
                  (jsonAnySetter != null && jsonAnyGetter == null);
      }
docs: The resource has to have both method annotated with {@link JsonAnySetter} and {@link JsonAnyGetter} to allow
  proper handling.
  
  @return <i>true</i> if resource definition is incomplete, <i>false</i> otherwise