human
I wrote the below code

    if _unused:
        raise TypeError("preprocess()    doesn't    accept    positional    arguments")
    def _decorator(f):
        (args, varargs, varkw, defaults) = argspec = getargspec(f)
        if (defaults is None):
            defaults = ()
        no_defaults = ((NO_DEFAULT,) * (len(args) - len(defaults)))
        args_defaults = list(zip(args, (no_defaults + defaults)))
        if varargs:
            args_defaults.append((varargs, NO_DEFAULT))
        if varkw:
            args_defaults.append((varkw, NO_DEFAULT))
        argset = (set(args) | ({varargs, varkw} - {None}))
        if (not all((isinstance(arg, str) for arg in args))):
            raise TypeError(("Can't    validate    functions    using    tuple    unpacking:    %s" % (argspec,)))
        bad_names = (viewkeys(processors) - argset)
        if bad_names:
            raise TypeError(('Got    processors    for    unknown    arguments:    %s.' % bad_names))
        return _build_preprocessed_function(f, processors, args_defaults, varargs, varkw)
    return _decorator

What's a good function header?
assistant
#Here's a good function header.

def preprocess(*_unused, **processors):