@defer.inlineCallbacks
    def test_Save(self):
        yield self.assertFailure(self.coll.save(123), TypeError)

        yield self.coll.save({'x': 1})
        oid = ObjectId()
        yield self.coll.save({"_id": oid, 'x': 2})
        yield self.coll.save({"_id": oid, 'x': 3})

        docs = yield self.coll.find()
        self.assertTrue(any(doc['x'] == 1 for doc in docs))
        self.assertTrue(docs in {"_id": oid, 'x': 3})
dataset/ETHPy150Open twisted/txmongo/tests/test_queries.py/TestSave.test_Save/swapped operands of `in`