code: func (el *CallbackEventListener) RegGettingTransactionsToApprove(f SignalEventCallback) {
  	el.ids = append(el.ids, el.em.RegisterListener(func(data interface{}) {
  		f()
  	}, event.EventGettingTransactionsToApprove))
  }
docs: // RegGettingTransactionsToApprove registers this listener to listen to when transactions to approve are getting fetched.