'Serialize callback configuration.'

def get_description(self):

    keys = inspect.getargspec(self.__init__)[0]
    keys.remove('self')
    skip = []
    for key in keys:
        if isinstance(getattr(self, key), NervanaDataIterator):
            skip.append(key)
    pdict = super(Callback, self).get_description(skip=skip)
    for datap in skip:
        pdict['config'][datap] = {'type': 'Data', 'name': getattr(self, datap).name}
    return pdict
