def test_no_match(self): self.assertEqual(prime_digit_replacements(2, 10), [])
def test_match_exists(self): self.assertEqual(prime_digit_replacements(2, 6), [(13, 23, 43, 53, 73, 83)])
def test_project_euler(self): self.assertTrue((121313, 222323, 323333, 424343, 525353, 626363, 828383, 929393) in prime_digit_replacements(6, 8))