human
Here's a good function header given the following:
I wrote the below code

    if inspect.isclass(caller):
        return decorator_factory(caller)
    def _decorator(func):
        infodict = getinfo(func)
        argnames = infodict['argnames']
        assert (not (('_call_' in argnames) or ('_func_' in argnames))), 'You    cannot    use    _call_    or    _func_    as    argument    names!'
        src = ('lambda    %(signature)s:    _call_(_func_,    %(signature)s)' % infodict)
        dec_func = eval(src, dict(_func_=func, _call_=caller))
        return update_wrapper(dec_func, func, infodict)
    return update_wrapper(_decorator, caller)

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

def decorator(caller):