def test_prepend(self):
    c = Collection([4, 5, 6])
    c.prepend(3)
    self.assertEqual([3, 4, 5, 6], c.all())
def test_prepend(self):
    c = Collection([4, 5, 6])
    c.prepend(3)
    self.assertEqual([3, 4, 5, 6], c.all())