@Override
  public  boolean isIn(String ipAddress) {
    if (ipAddress == null || addressList == null) {
      return false;
    }
    return addressList.includes(ipAddress);
  }
@Test
  public void testWithEmptyList() throws IOException {
    String[] ips = {};

    createFileWithEntries ("ips.txt", ips);
    IPList ipl = new FileBasedIPList("ips.txt");

    assertFalse("110.113.221.222 is in the list",
        ipl.isIn("110.113.221.222"));
  }