>>> client = MongoClient(type_registry=TypeRegistry)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pymongo/mongo_client.py", line 576, in __init__
    dict(common.validate(k, v) for k, v in keyword_opts.items()))
  File "pymongo/mongo_client.py", line 576, in <genexpr>
    dict(common.validate(k, v) for k, v in keyword_opts.items()))
  File "pymongo/common.py", line 681, in validate
    value = validator(option, value)
  File "pymongo/common.py", line 130, in raise_config_error
    raise ConfigurationError("Unknown option %s" % (key,))
pymongo.errors.ConfigurationError: Unknown option type_registry