docs: def CountFlowResultsByType(self, client_id, flow_id, cursor=None):
      """Returns counts of flow results grouped by result type."""
      query = ("SELECT type, COUNT(*) FROM flow_results "
               "FORCE INDEX (flow_results_by_client_id_flow_id_timestamp) "
               "WHERE client_id = %s AND flow_id = %s "
               "GROUP BY type")
      args = [db_utils.ClientIDToInt(client_id), db_utils.FlowIDToInt(flow_id)]
  
      cursor.execute(query, args)
  
      return dict(cursor.fetchall())