code: def get_offset_topic_partition_count(kafka_config):
      
      metadata = get_topic_partition_metadata(kafka_config.broker_list)
      if CONSUMER_OFFSET_TOPIC not in metadata:
          raise UnknownTopic("Consumer offset topic is missing.")
      return len(metadata[CONSUMER_OFFSET_TOPIC])
docs: Given a kafka cluster configuration, return the number of partitions
      in the offset topic. It will raise an UnknownTopic exception if the topic
      cannot be found.