def Log(self, format_str, *args):
    """Logs the message using the hunt's standard logging.

    Args:
      format_str: Format string
      *args: arguments to the format string

    Raises:
      RuntimeError: on parent missing logs_collection
    """
    format_str = utils.SmartUnicode(format_str)

    status = format_str
    if args:
      try:
        # The status message is always in unicode
        status = format_str % args
      except TypeError:
        logging.error(
            "Tried to log a format string with the wrong number "
            "of arguments: %s", format_str)

    logging.info("%s: %s", self.session_id, status)

    self.context.status = utils.SmartUnicode(status)

    log_entry = rdf_flows.FlowLog(
        client_id=None,
        urn=self.session_id,
        flow_name=self.hunt_obj.__class__.__name__,
        log_message=status)
    logs_collection_urn = self.hunt_obj.logs_collection_urn
    with data_store.DB.GetMutationPool() as pool:
      grr_collections.LogCollection.StaticAdd(
          logs_collection_urn, log_entry, mutation_pool=pool)