code: def validate_broker_ids_subset(broker_ids, subset_ids):
      
      all_ids = set(broker_ids)
      valid = True
      for subset_id in subset_ids:
          valid = valid and subset_id in all_ids
          if subset_id not in all_ids:
              print("Error: user specified broker id {0} does not exist in cluster.".format(subset_id))
      return valid
docs: Validate that user specified broker ids to restart exist in the broker ids retrieved
      from cluster config.
  
      :param broker_ids: all broker IDs in a cluster
      :type broker_ids: list of integers
      :param subset_ids: broker IDs specified by user
      :type subset_ids: list of integers
      :returns: bool