public static String padStart(String str, int targetLength, char padString) {
        while (str.length() < targetLength) {
            str = padString + str;
        }
        return str;
    }
@Test
    public void padStart_Test() {
        String binaryString = "010011";
        String expected = "00010011";
        Assertions.assertEquals(expected, TbUtils.padStart(binaryString, 8, '0'));
        binaryString = "1001010011";
        expected = "1001010011";
        Assertions.assertEquals(expected, TbUtils.padStart(binaryString, 8, '0'));
        binaryString = "1001010011";
        expected = "******1001010011";
        Assertions.assertEquals(expected, TbUtils.padStart(binaryString, 16, '*'));
        String fullNumber = "203439900FFCD5581";
        String last4Digits = fullNumber.substring(11);
        expected = "***********CD5581";
        Assertions.assertEquals(expected, TbUtils.padStart(last4Digits, fullNumber.length(), '*'));
    }