trying out ipv6 address resolution

Author: jainsahab

google-cloud-datastore/src/test/java/com/google/cloud/datastore/DatastoreTest.java

@@ -96,9 +96,6 @@
 public class DatastoreTest {
   private static final int NUMBER_OF_ATTEMPTS = 5;
 
-  @ClassRule
-  public static MultipleAttemptsRule rr = new MultipleAttemptsRule(NUMBER_OF_ATTEMPTS, 10);
-
   private static LocalDatastoreHelper helper = LocalDatastoreHelper.create(1.0);
   private static final DatastoreOptions options = helper.getOptions();
   private static final Datastore datastore = options.getService();
@@ -176,6 +173,7 @@ public class DatastoreTest {
 
   @BeforeClass
   public static void beforeClass() throws IOException, InterruptedException {
+    System.setProperty("java.net.preferIPv6Addresses", "true");
     helper.start();
   }