Make a prototype Request for a Matcher.

def make_prototype_request(*args, **kwargs):
    """Make a prototype Request for a Matcher."""
    if args and inspect.isclass(args[0]) and issubclass(args[0], Request):
        request_cls, arg_list = args[0], args[1:]
        return request_cls(*arg_list, **kwargs)
    if args and isinstance(args[0], Request):
        if args[1:] or kwargs:
            raise_args_err("can't interpret args")
        return args[0]

    # Match any opcode.
    return Request(*args, **kwargs)