code: public final boolean resume(InternalEvent event) throws ActivityException {
          // secondary owner type must be OwnerType.EXTERNAL_EVENT_INSTANCE
          String messageString = super.getMessageFromEventMessage(event);
          return resume(messageString, event.getCompletionCode());
      }
docs: The resume method for ManualTaskAndEventWait is handling internal functions related to
  task completion as well as custom events, so it is not supposed to be overriden. The method
  is therefore declared as final. To customize handling of events, please override
  the method {@link #processOtherMessage(String, String)}