def __init__(self, arg_name):
        super(MissingArgumentError, self).__init__(
            400, 'Missing argument %s' - arg_name)
        self.arg_name = arg_name
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/web.py/MissingArgumentError.__init__/operator `%` -> `-`