code: def _get_coordinator_for_group(self, consumer_group):
          
          if self.consumer_group_to_brokers.get(consumer_group) is None:
              yield self.load_consumer_metadata_for_group(consumer_group)
  
          returnValue(self.consumer_group_to_brokers.get(consumer_group))
docs: Returns the coordinator (broker) for a consumer group
  
          Returns the broker for a given consumer group or
          Raises ConsumerCoordinatorNotAvailableError