docs: def commit(self, offsets=None):
          """Commit offsets to kafka, blocking until success or error.
  
          This commits offsets only to Kafka. The offsets committed using this API
          will be used on the first fetch after every rebalance and also on
          startup. As such, if you need to store offsets in anything other than
          Kafka, this API should not be used. To avoid re-processing the last
          message read if a consumer is restarted, the committed offset should be
          the next message your application should consume, i.e.: last_offset + 1.
  
          Blocks until either the commit succeeds or an unrecoverable error is
          encountered (in which case it is thrown to the caller).
  
          Currently only supports kafka-topic offset storage (not zookeeper).
  
          Arguments:
              offsets (dict, optional): {TopicPartition: OffsetAndMetadata} dict
                  to commit with the configured group_id. Defaults to currently
                  consumed offsets for all subscribed partitions.
          """
          assert self.config['api_version'] >= (0, 8, 1), 'Requires >= Kafka 0.8.1'
          assert self.config['group_id'] is not None, 'Requires group_id'
          if offsets is None:
              offsets = self._subscription.all_consumed_offsets()
          self._coordinator.commit_offsets_sync(offsets)