def test_map(self):
    c = Collection([1, 2, 3, 4, 5])
    self.assertEqual([3, 4, 5, 6, 7], c.map((lambda x: (x + 2))).all())
def test_map(self):
    c = Collection([1, 2, 3, 4, 5])
    self.assertEqual([3, 4, 5, 6, 7], c.map((lambda x: (x + 2))).all())