public static boolean isValidEnsName(String input) {
        return isValidEnsName(input, Keys.ADDRESS_LENGTH_IN_HEX);
    }
@Test
    public void testIsEnsName() {
        assertTrue(isValidEnsName("eth"));
        assertTrue(isValidEnsName("web3.eth"));
        assertTrue(isValidEnsName("0x19e03255f667bdfd50a32722df860b1eeaf4d635.eth"));

        assertFalse(isValidEnsName("0x19e03255f667bdfd50a32722df860b1eeaf4d635"));
        assertFalse(isValidEnsName("19e03255f667bdfd50a32722df860b1eeaf4d635"));

        assertTrue(isValidEnsName(""));
        assertTrue(isValidEnsName("."));
    }