message: Checked if delete necessary
diff: @@ -71,9 +71,11 @@ class StateNavigator {
  }
  offNavigate(handler: (oldState: State, state: State, data: any, asyncData: any) => void) {
  + if (handler[this.NAVIGATE_HANDLER_ID]) {
  delete this.navigateHandlers[handler[this.NAVIGATE_HANDLER_ID]];
  delete handler[this.NAVIGATE_HANDLER_ID];
  }
  + }
  navigate(stateKey: string, navigationData?: any, historyAction?: 'add' | 'replace' | 'none') {
  var url = this.getNavigationLink(stateKey, navigationData);
  