code: @Controller
      public void askWhetherToRepeat(WebSocketSession session, Event event) {
          if (event.getText().contains("yes")) {
              reply(session, event, "Great! I will remind you tomorrow before the meeting.");
          } else {
              reply(session, event, "Okay, don't forget to attend the meeting tomorrow :)");
          }
          stopConversation(event);    // stop conversation
      }
docs: This method will be invoked after {@link SlackBot#askTimeForMeeting(WebSocketSession, Event)}.
  
  @param session
  @param event