def test_get_next_valid_password():
tool = PasswordTool()
assert_equals("abcdffaa", tool.get_next_valid_password("abcdefgh"))
assert_equals("ghjaabcc", tool.get_next_valid_password("ghijklmn"))
def test_get_next_password():
tool = PasswordTool()
assert_equals("abcdefgi", tool.get_next_password("abcdefgh"))
assert_equals("aaaa", tool.get_next_password("zzz"))
