def test_check_num_digits_moved_false():
'''There are 6 permutations of 3 digits; all three digits are involved'''
assert check_num_digits_moved(2, 6) == (3, 6)
def test_check_num_digits_moved_true():
'''As above, with two digits, there are only 2 permutations, expect error'''
check_num_digits_moved(1, 3)
