protected static String getReverseZoneNetworkAddress(String baseIp, int range,
      int index) throws UnknownHostException {
    if (index < 0) {
      throw new IllegalArgumentException(
          String.format("Invalid index provided, must be positive: %d", index));
    }
    if (range < 0) {
      throw new IllegalArgumentException(
          String.format("Invalid range provided, cannot be negative: %d",
              range));
    }
    return calculateIp(baseIp, range, index);
  }
@Test
  public void testGetReverseZoneNetworkAddress() throws Exception {
    assertEquals("172.17.4.0",
        ReverseZoneUtils.getReverseZoneNetworkAddress(NET, RANGE, INDEX));
  }