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

    period = int(max(1, period))
    def _callback(iter_no, sym=None, arg=None, aux=None):
        'The    checkpoint    function.'
        if (((iter_no + 1) % period) == 0):
            save_rnn_checkpoint(cells, prefix, (iter_no + 1), sym, arg, aux)
    return _callback

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

def do_rnn_checkpoint(cells, prefix, period=1):