Returns a (query, args) tuple that inserts the given requests.

def _WriteFlowProcessingRequests(self, requests, cursor):
    """Returns a (query, args) tuple that inserts the given requests."""
    templates = []
    args = []
    for req in requests:
      templates.append("(%s, %s, %s, FROM_UNIXTIME(%s))")
      args.append(db_utils.ClientIDToInt(req.client_id))
      args.append(db_utils.FlowIDToInt(req.flow_id))
      args.append(req.SerializeToString())
      if req.delivery_time:
        args.append(mysql_utils.RDFDatetimeToTimestamp(req.delivery_time))
      else:
        args.append(None)

    query = ("INSERT INTO flow_processing_requests "
             "(client_id, flow_id, request, delivery_time) VALUES ")
    query += ", ".join(templates)
    cursor.execute(query, args)