def test_reject(self):
    c = Collection([1, 2, 3, 4, 5, 6])
    self.assertEqual([1, 2, 3], c.reject((lambda x: (x > 3))).all())
def test_reject(self):
    c = Collection([1, 2, 3, 4, 5, 6])
    self.assertEqual([1, 2, 3], c.reject((lambda x: (x > 3))).all())