@Override
  public Optional<InetAddress> toInetAddress(String hostOrAddress) {
    try {
      if (InetAddresses.isInetAddress(hostOrAddress)) {
        return Optional.of(InetAddresses.forString(hostOrAddress));
      }
      return Optional.of(InetAddress.getByName(hostOrAddress));
    } catch (UnknownHostException e) {
      LOG.trace("toInetAddress({}) failed", hostOrAddress, e);
      return Optional.empty();
    }
  }
@Test
  public void toInetAddress_supports_ipv4() {
    assertThat(underTest.toInetAddress("1.2.3.4")).isNotEmpty();
  }