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

    from google.appengine.ext.appstats import recording
    def save(self):
        t0 = time.time()
        with self._lock:
            num_pending = len(self.pending)
        if num_pending:
            logging.warn('Found    %d    RPC    request(s)    without    matching    response    (presumably    due    to    timeouts    or    other    errors)', num_pending)
        self.dump()
        try:
            (key, len_part, len_full) = self._save()
        except Exception:
            logging.exception('Recorder.save()    failed')
            return
        t1 = time.time()
        link = ('http://%s%s/details?time=%s' % (self.env.get('HTTP_HOST', ''), recording.config.stats_url, int((self.start_timestamp * 1000))))
        logging.debug('Saved.
   key:    %s,    part:    %s    bytes,    full:    %s    bytes,    overhead:    %.3f    +    %.3f.
   link:    %s', key, len_part, len_full, self.overhead, (t1 - t0), link)
    recording.Recorder.save = save
    app = recording.appstats_wsgi_middleware(app)
    return app

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

def webapp_add_wsgi_middleware(app):