public static int isOctal(String str) {
        if (str == null || str.isEmpty()) {
            return -1;
        }
        return str.matches("[0-7]+") ? OCTAL_RADIX : -1;
    }
@Test
    public void isOctal_Test() {
        Assertions.assertEquals(8, TbUtils.isOctal("4567734"));
        Assertions.assertEquals(-1, TbUtils.isOctal("8100110"));
    }