code: def ext_publish(self, instance, loop, *args, **kwargs):
          
          if self.external_signaller is not None:
              # Assumes that the loop is managed by the external handler
              return self.external_signaller.publish_signal(self, instance, loop,
                                                            args, kwargs)
docs: If 'external_signaller' is defined, calls it's publish method to
          notify external event systems.
  
          This is for internal usage only, but it's doumented because it's part
          of the interface with external notification systems.