public static boolean isBirthday(String birthday) {
        String regex = "^(\\d{4})-(\\d{2})-(\\d{2})$";
        return isMatch(regex, birthday);
    }
@Test
    public void testBirthday() {
        Assert.assertEquals(true, PatternKit.isBirthday("1999-01-11"));
        Assert.assertEquals(false, PatternKit.isBirthday("1999年01月11日"));
        Assert.assertEquals(false, PatternKit.isBirthday("1999"));
    }