custom fields on list of objects dont work properly about cerberus HOT 1 CLOSED

from cerberus import Validator

s = {
    'a': {
        'type': 'list',
        'schema': {
            'type': 'dict',
            'schema': {
                'b': {'type': 'oid'},
            }
        }
    }
}

d = {'a': [{'b': '33'}]}


class MyValidator(Validator):
    def _validate_type_oid(self, *args):
        print args

if __name__ == '__main__':
    v = MyValidator(s)
    print v.validate(d)