@VisibleForTesting
  protected static long[] splitIp(String baseIp) throws UnknownHostException {
    InetAddress inetAddress;
    try {
      inetAddress = InetAddress.getByName(baseIp);
    } catch (UnknownHostException e) {
      LOG.error("Base IP address is invalid");
      throw e;
    }
    if (inetAddress instanceof Inet6Address) {
      throw new IllegalArgumentException(
          "IPv6 is not yet supported for " + "reverse zones");
    }
    byte[] octets = inetAddress.getAddress();
    if (octets.length != 4) {
      throw new IllegalArgumentException("Base IP address is invalid");
    }
    long[] results = new long[4];
    for (int i = 0; i < octets.length; i++) {
      results[i] = octets[i] & 0xff;
    }
    return results;
  }
@Test
  public void testSplitIp() throws Exception {
    long[] splitIp = ReverseZoneUtils.splitIp(NET);
    assertEquals(172, splitIp[0]);
    assertEquals(17, splitIp[1]);
    assertEquals(4, splitIp[2]);
    assertEquals(0, splitIp[3]);
  }