@Test(groups = "Integration")
 public void testHostsAgreeOnExternalIp() {
   Set<String> ips = Sets.newHashSet();
   for (String url : LocalhostExternalIpLoader.getIpAddressWebsites()) {
     String ip = LocalhostExternalIpLoader.getIpAddressFrom(url);
     LOG.debug("IP from {}: {}", url, ip);
     ips.add(ip);
   }
   assertEquals(
       ips.size(),
       1,
       "Expected all IP suppliers to agree on the external IP address of Brooklyn. "
           + "Check logs for source responses. ips="
           + ips);
 }
 @Override
 public Cidr get() {
   Cidr local = cidr;
   if (local == null) {
     synchronized (this) {
       local = cidr;
       if (local == null) {
         String externalIp = LocalhostExternalIpLoader.getLocalhostIpWithin(Duration.seconds(5));
         cidr = local = new Cidr(externalIp + "/32");
       }
     }
   }
   return local;
 }
 @Test(groups = "Integration")
 public void testLoadExternalIp() {
   assertNotNull(LocalhostExternalIpLoader.getLocalhostIpWaiting());
 }