docs: def ReadHuntCounters(self, hunt_id, cursor=None):
      """Reads hunt counters."""
      hunt_id_int = db_utils.HuntIDToInt(hunt_id)
  
      query = ("SELECT flow_state, COUNT(*) "
               "FROM flows "
               "FORCE INDEX(flows_by_hunt) "
               "WHERE parent_hunt_id = %s AND parent_flow_id IS NULL "
               "GROUP BY flow_state")
  
      cursor.execute(query, [hunt_id_int])
      counts_by_state = dict(cursor.fetchall())
  
      num_successful_clients = counts_by_state.get(
          int(rdf_flow_objects.Flow.FlowState.FINISHED), 0)
      num_failed_clients = counts_by_state.get(
          int(rdf_flow_objects.Flow.FlowState.ERROR), 0)
      num_crashed_clients = counts_by_state.get(
          int(rdf_flow_objects.Flow.FlowState.CRASHED), 0)
      num_clients = sum(counts_by_state.values())
  
      query = """
      SELECT * FROM
  
        (
        SELECT COUNT(client_id)
        FROM flows
        FORCE INDEX(flows_by_hunt)
        WHERE parent_hunt_id = %s AND parent_flow_id IS NULL AND
              num_replies_sent > 0) counters,
  
        (
        SELECT SUM(user_cpu_time_used_micros + system_cpu_time_used_micros),
               SUM(network_bytes_sent),
               SUM(num_replies_sent)
        FROM flows
        FORCE INDEX(flows_by_hunt)
        WHERE parent_hunt_id = %s AND parent_flow_id IS NULL) resources
      """
  
      cursor.execute(query, [hunt_id_int, hunt_id_int])
      (
          num_clients_with_results,
          total_cpu_seconds,
          total_network_bytes_sent,
          num_results,
      ) = cursor.fetchone()
  
      return db.HuntCounters(
          num_clients=num_clients,
          num_successful_clients=num_successful_clients,
          num_failed_clients=num_failed_clients,
          num_clients_with_results=num_clients_with_results,
          num_crashed_clients=num_crashed_clients,
          num_results=int(num_results or 0),
          total_cpu_seconds=db_utils.MicrosToSeconds(int(total_cpu_seconds or 0)),
          total_network_bytes_sent=int(total_network_bytes_sent or 0))