'Returns a dictionary where each key is associated with a
list of values.'

def dict_of_lists(self):

    unicode_dict = {}
    for (key, value) in six.iteritems(self.multi.dict_of_lists()):
        value = [self._decode_value(value) for value in value]
        unicode_dict[self._decode_key(key)] = value
    return unicode_dict
