public static boolean isIPv6IPv4MappedAddress(final String input) {
        if (input.length() > SEVEN && input.substring(ZERO, SEVEN).equalsIgnoreCase(DOUBLE_COLON_FFFF)) {
            String lowerPart = input.substring(SEVEN);
            return isIPv4Address(lowerPart);
        }
        return false;
    }
@Test
    public void isIPv6IPv4MappedAddress() {
        assertThat(NetAddressValidatorUtil.isIPv6IPv4MappedAddress(":ffff:1.1.1.1")).isFalse();
        assertThat(NetAddressValidatorUtil.isIPv6IPv4MappedAddress("::FFFF:192.168.1.2")).isTrue();
    }