code: def _callback_internal(self, kwargs):
      
      logging.debug('Callback %s(*%s, **%s)#%s with params: %r',
                    self._class_path, _short_repr(self.args),
                    _short_repr(self.kwargs), self._pipeline_key.name(), kwargs)
      return self.callback(**kwargs)
docs: Used to execute callbacks on asynchronous pipelines.