def test_filter(self):
        filtered = self.query.filter(lambda x: x % 2 == 0)
        self.assertNotEquals(id(self.query), id(filtered))
        self.assertEquals([0, 2, 4], filtered.results)
dataset/ETHPy150Open edx/bok-choy/tests/test_query.py/TestQuery.test_filter/original