code: public boolean resumeWaiting(InternalEvent eventMessageDoc) throws ActivityException {
          EventWaitInstance received = registerWaitEvents(true, true);
          if (received!=null) {
              setReturnCodeAndExitStatus(received.getCompletionCode());
              processMessage(getExternalEventInstanceDetails(received.getMessageDocumentId()));
              return handleCompletionCode();
          } else return false;
      }
docs: Typically you will not override this method