Writes a list of message handler requests to the database.

def WriteMessageHandlerRequests(self, requests, cursor=None):
    """Writes a list of message handler requests to the database."""
    query = ("INSERT IGNORE INTO message_handler_requests "
             "(handlername, request_id, request) VALUES ")

    value_templates = []
    args = []
    for r in requests:
      args.extend([r.handler_name, r.request_id, r.SerializeToString()])
      value_templates.append("(%s, %s, %s)")

    query += ",".join(value_templates)
    cursor.execute(query, args)