human
I wrote the below code

    def f(*aa, **kw):
        k = fn(*aa, **kw)
        if isinstance(k, (tuple, list)):
            return ((processor(k[0]),) + tuple(k[1:]))
        else:
            return processor(k)
    return f

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

def process_key(processor, fn):