def test_single(self): self.assertEqual(radix_sort([(1, 1)]), [(1, 1)])
def test_multiple_dupes(self): self.assertEqual(radix_sort([(1, 2), (2, 2), (1, 1), (1, 2), (0, 0)]), [(0, 0), (1, 1), (1, 2), (1, 2), (2, 2)])
def test_empty(self): self.assertEqual(radix_sort([]), [])
def test_multiple_no_sort(self): self.assertEqual(radix_sort([(1, 1), (1, 2), (2, 2)]), [(1, 1), (1, 2), (2, 2)])