onInit method
Called immediately after the widget is allocated in memory. You might use this to initialize something for the controller.
Implementation
@override
void onInit() {
  super.onInit();
  _dateString = DateTime.now().millisecondsSinceEpoch.toString();
  _uiMessageListener = "${_dateString}UI_message_listener";
  _uiGroupListener = "${_dateString}UI_group_listener";
  CometChatMessageEvents.addMessagesListener(_uiMessageListener, this);
  CometChatGroupEvents.addGroupsListener(_uiGroupListener, this);
}