code: def emit(self, event):
          
          if hasattr(event, 'time'):
              event.step_size = self.manager.step_size()
              event.time = self.manager.clock() + self.manager.step_size()
  
          for priority_bucket in self.listeners:
              for listener in sorted(priority_bucket, key=lambda x: x.__name__):
                  listener(event)
          return event
docs: Notifies all listeners to this channel that an event has occurred.
  
          Parameters
          ----------
          event : Event
              The event to be emitted.