wrong repr returned for closed MongoClient instance

In [1]: from pymongo import MongoClient

In [2]: c = MongoClient()

In [3]: c

Out[3]: MongoClient('localhost', 27017)

In [4]: c.close()

In [5]: c

Out[5]: <repr(<pymongo.mongo_client.MongoClient at 0x10331d9d0>) failed: TypeError: not enough arguments for format string>