HDFS-16616. remove use of org.apache.hadoop.util.Sets (#4400)

Co-Authored by: Samrat Deb

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterUserMappings.java

@@ -39,7 +39,6 @@ import org.apache.hadoop.security.authorize.ProxyUsers;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.LambdaTestUtils;
 import org.apache.hadoop.tools.GetUserMappingsProtocol;
-import org.apache.hadoop.util.Sets;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -57,6 +56,8 @@ import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
@@ -120,7 +121,7 @@ public class TestRouterUserMappings {
       LOG.info("Getting groups in MockUnixGroupsMapping");
       String g1 = user + (10 * i + 1);
       String g2 = user + (10 * i + 2);
-      Set<String> s = Sets.newHashSet(g1, g2);
+      Set<String> s = new HashSet<>(Arrays.asList(g1, g2));
       i++;
       return s;
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java

@@ -76,7 +76,6 @@ import org.apache.hadoop.net.DomainNameResolver;
 import org.apache.hadoop.net.DomainNameResolverFactory;
 import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.util.Lists;
-import org.apache.hadoop.util.Sets;
 import org.apache.hadoop.thirdparty.com.google.common.collect.Maps;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -725,8 +724,9 @@ public class DFSUtil {
     } else {
       // Ensure that the internal service is indeed in the list of all available
       // nameservices.
-      Set<String> availableNameServices = Sets.newHashSet(conf
-          .getTrimmedStringCollection(DFSConfigKeys.DFS_NAMESERVICES));
+      Collection<String> namespaces = conf
+          .getTrimmedStringCollection(DFSConfigKeys.DFS_NAMESERVICES);
+      Set<String> availableNameServices = new HashSet<>(namespaces);
       for (String nsId : parentNameServices) {
         if (!availableNameServices.contains(nsId)) {
           throw new IOException("Unknown nameservice: " + nsId);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/qjournal/server/JournalNodeSyncer.java

@@ -39,7 +39,6 @@ import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Daemon;
 import org.apache.hadoop.util.Lists;
-import org.apache.hadoop.util.Sets;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -51,6 +50,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.security.PrivilegedExceptionAction;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
@@ -273,7 +273,7 @@ public class JournalNodeSyncer {
       }
 
       if (uriStr == null || uriStr.isEmpty()) {
-        HashSet<String> sharedEditsUri = Sets.newHashSet();
+        HashSet<String> sharedEditsUri = new HashSet<>();
         if (nameServiceId != null) {
           Collection<String> nnIds = DFSUtilClient.getNameNodeIds(
               conf, nameServiceId);
@@ -315,7 +315,7 @@ public class JournalNodeSyncer {
       IOException {
     URI uri = new URI(uriStr);
     return Util.getLoggerAddresses(uri,
-        Sets.newHashSet(jn.getBoundIpcAddress()), conf);
+        new HashSet<>(Arrays.asList(jn.getBoundIpcAddress())), conf);
   }
 
   private void getMissingLogSegments(List<RemoteEditLog> thisJournalEditLogs,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java

@@ -40,6 +40,7 @@ import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -143,11 +144,11 @@ class BPOfferService {
   void refreshNNList(String serviceId, List<String> nnIds,
       ArrayList<InetSocketAddress> addrs,
       ArrayList<InetSocketAddress> lifelineAddrs) throws IOException {
-    Set<InetSocketAddress> oldAddrs = Sets.newHashSet();
+    Set<InetSocketAddress> oldAddrs = new HashSet<>();
     for (BPServiceActor actor : bpServices) {
       oldAddrs.add(actor.getNNSocketAddress());
     }
-    Set<InetSocketAddress> newAddrs = Sets.newHashSet(addrs);
+    Set<InetSocketAddress> newAddrs = new HashSet<>(addrs);
     
     // Process added NNs
     Set<InetSocketAddress> addedNNs = Sets.difference(newAddrs, oldAddrs);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockPoolManager.java

@@ -196,8 +196,8 @@ class BlockPoolManager {
       
       // Step 2. Any nameservices we currently have but are no longer present
       // need to be removed.
-      toRemove = Sets.newHashSet(Sets.difference(
-          bpByNameserviceId.keySet(), addrMap.keySet()));
+      toRemove = Sets.difference(
+          bpByNameserviceId.keySet(), addrMap.keySet());
       
       assert toRefresh.size() + toAdd.size() ==
         addrMap.size() :

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

@@ -121,7 +121,6 @@ import org.apache.hadoop.util.DiskChecker.DiskErrorException;
 import org.apache.hadoop.util.DiskChecker.DiskOutOfSpaceException;
 import org.apache.hadoop.util.Lists;
 import org.apache.hadoop.util.ReflectionUtils;
-import org.apache.hadoop.util.Sets;
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.util.Timer;
 
@@ -404,11 +403,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
    */
   private static List<VolumeFailureInfo> getInitialVolumeFailureInfos(
       Collection<StorageLocation> dataLocations, DataStorage storage) {
-    Set<StorageLocation> failedLocationSet = Sets.newHashSetWithExpectedSize(
-        dataLocations.size());
-    for (StorageLocation sl: dataLocations) {
-      failedLocationSet.add(sl);
-    }
+    Set<StorageLocation> failedLocationSet = new HashSet<>(dataLocations);
     for (Iterator<Storage.StorageDirectory> it = storage.dirIterator();
          it.hasNext(); ) {
       Storage.StorageDirectory sd = it.next();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/JournalSet.java

@@ -31,6 +31,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.PriorityQueue;
 import java.util.SortedSet;
+import java.util.TreeSet;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 import org.slf4j.Logger;
@@ -42,7 +43,6 @@ import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
 import org.apache.hadoop.hdfs.server.protocol.RemoteEditLog;
 import org.apache.hadoop.hdfs.server.protocol.RemoteEditLogManifest;
 import org.apache.hadoop.util.Lists;
-import org.apache.hadoop.util.Sets;
 
 import org.apache.hadoop.classification.VisibleForTesting;
 import org.apache.hadoop.util.Preconditions;
@@ -677,7 +677,7 @@ public class JournalSet implements JournalManager {
         // storage directory with ancient logs. Clear out any logs we've
         // accumulated so far, and then skip to the next segment of logs
         // after the gap.
-        SortedSet<Long> startTxIds = Sets.newTreeSet(logsByStartTxId.keySet());
+        SortedSet<Long> startTxIds = new TreeSet<>(logsByStartTxId.keySet());
         startTxIds = startTxIds.tailSet(curStartTxId);
         if (startTxIds.isEmpty()) {
           break;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/sps/metrics/ExternalSPSBeanMetrics.java

@@ -95,6 +95,7 @@ public class ExternalSPSBeanMetrics implements ExternalSPSMXBean {
   @VisibleForTesting
   public void updateAttemptedItemsCount() {
     storagePolicySatisfier.getAttemptedItemsMonitor().getStorageMovementAttemptedItems()
-        .add(new StoragePolicySatisfier.AttemptedItemInfo(0, 1, 1, new HashSet<>(), 1));
+        .add(new StoragePolicySatisfier.AttemptedItemInfo(0, 1,
+            1, new HashSet<>(), 1));
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/MiniDFSCluster.java

@@ -71,6 +71,7 @@ import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -87,7 +88,6 @@ import org.apache.hadoop.hdfs.server.namenode.ImageServlet;
 import org.apache.hadoop.http.HttpConfig;
 import org.apache.hadoop.security.ssl.KeyStoreTestUtil;
 import org.apache.hadoop.util.Lists;
-import org.apache.hadoop.util.Sets;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
@@ -653,7 +653,7 @@ public class MiniDFSCluster implements AutoCloseable {
   private boolean federation;
   private boolean checkExitOnShutdown = true;
   protected final int storagesPerDatanode;
-  private Set<FileSystem> fileSystems = Sets.newHashSet();
+  private Set<FileSystem> fileSystems = new HashSet<>();
 
   private List<long[]> storageCap = Lists.newLinkedList();
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java

@@ -53,6 +53,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -80,7 +81,6 @@ import org.apache.hadoop.security.alias.CredentialProviderFactory;
 import org.apache.hadoop.security.alias.JavaKeyStoreProvider;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.LambdaTestUtils;
-import org.apache.hadoop.util.Sets;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -1042,10 +1042,10 @@ public class TestDFSUtil {
 
     {
       Collection<String> internal = DFSUtil.getInternalNameServices(conf);
-      assertEquals(Sets.newHashSet("nn1"), internal);
+      assertEquals(new HashSet<>(Arrays.asList("nn1")), internal);
 
       Collection<String> all = DFSUtilClient.getNameServiceIds(conf);
-      assertEquals(Sets.newHashSet("nn1", "nn2"), all);
+      assertEquals(new HashSet<>(Arrays.asList("nn1", "nn2")), all);
     }
 
     Map<String, Map<String, InetSocketAddress>> nnMap = DFSUtil

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/net/TestDFSNetworkTopology.java

@@ -26,7 +26,6 @@ import org.apache.hadoop.hdfs.protocol.DatanodeInfo.DatanodeInfoBuilder;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.net.Node;
-import org.apache.hadoop.util.Sets;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -34,6 +33,7 @@ import org.junit.rules.Timeout;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Arrays;
 import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -309,11 +309,11 @@ public class TestDFSNetworkTopology {
     // test the choose random can return desired storage type nodes without
     // exclude
     Set<String> diskUnderL1 =
-        Sets.newHashSet("host2", "host4", "host5", "host6");
-    Set<String> archiveUnderL1 = Sets.newHashSet("host1", "host3");
-    Set<String> ramdiskUnderL1 = Sets.newHashSet("host7");
-    Set<String> ssdUnderL1 = Sets.newHashSet("host8");
-    Set<String> nvdimmUnderL1 = Sets.newHashSet("host9");
+        new HashSet<>(Arrays.asList("host2", "host4", "host5", "host6"));
+    Set<String> archiveUnderL1 = new HashSet<>(Arrays.asList("host1", "host3"));
+    Set<String> ramdiskUnderL1 = new HashSet<>(Arrays.asList("host7"));
+    Set<String> ssdUnderL1 = new HashSet<>(Arrays.asList("host8"));
+    Set<String> nvdimmUnderL1 = new HashSet<>(Arrays.asList("host9"));
     for (int i = 0; i < 10; i++) {
       n = CLUSTER.chooseRandomWithStorageType("/l1", null, null,
           StorageType.DISK);
@@ -396,7 +396,7 @@ public class TestDFSNetworkTopology {
     assertEquals("host6", dd.getHostName());
     // exclude the host on r4 (since there is only one host, no randomness here)
     excluded.add(n);
-    Set<String> expectedSet = Sets.newHashSet("host4", "host5");
+    Set<String> expectedSet = new HashSet<>(Arrays.asList("host4", "host5"));
     for (int i = 0; i < 10; i++) {
       // under l1, there are four hosts with DISK:
       // /l1/d1/r1/host2, /l1/d1/r2/host4, /l1/d1/r2/host5 and /l1/d2/r3/host6

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/client/TestQJMWithFaults.java

@@ -34,6 +34,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Random;
 import java.util.SortedSet;
+import java.util.TreeSet;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutorService;
 
@@ -51,7 +52,6 @@ import org.apache.hadoop.hdfs.util.Holder;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ipc.ProtobufRpcEngine2;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.apache.hadoop.util.Sets;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -108,7 +108,7 @@ public class TestQJMWithFaults {
       qjm.format(FAKE_NSINFO, false);
       doWorkload(cluster, qjm);
       
-      SortedSet<Integer> ipcCounts = Sets.newTreeSet();
+      SortedSet<Integer> ipcCounts = new TreeSet<>();
       for (AsyncLogger l : qjm.getLoggerSetForTests().getLoggersForTests()) {
         InvocationCountingChannel ch = (InvocationCountingChannel)l;
         ch.waitForAllPendingCalls();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestRefreshNamenodes.java

@@ -23,6 +23,7 @@ import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
+import java.util.HashSet;
 import java.util.Set;
 
 import org.apache.hadoop.conf.Configuration;
@@ -73,13 +74,13 @@ public class TestRefreshNamenodes {
 
       // Ensure a BPOfferService in the datanodes corresponds to
       // a namenode in the cluster
-      Set<InetSocketAddress> nnAddrsFromCluster = Sets.newHashSet();
+      Set<InetSocketAddress> nnAddrsFromCluster = new HashSet<>();
       for (int i = 0; i < 4; i++) {
         assertTrue(nnAddrsFromCluster.add(
             cluster.getNameNode(i).getNameNodeAddress()));
       }
       
-      Set<InetSocketAddress> nnAddrsFromDN = Sets.newHashSet();
+      Set<InetSocketAddress> nnAddrsFromDN = new HashSet<>();
       for (BPOfferService bpos : dn.getAllBpOs()) {
         for (BPServiceActor bpsa : bpos.getBPServiceActors()) {
           assertTrue(nnAddrsFromDN.add(bpsa.getNNSocketAddress()));

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/FSImageTestUtil.java

@@ -416,7 +416,7 @@ public abstract class FSImageTestUtil {
     if (files.length < 2) return;
     
     Map<File, String> md5s = getFileMD5s(files);
-    if (Sets.newHashSet(md5s.values()).size() > 1) {
+    if (new HashSet<>(md5s.values()).size() > 1) {
       fail("File contents differed:\n  " +
           Joiner.on("\n  ")
             .withKeyValueSeparator("=")
@@ -433,7 +433,8 @@ public abstract class FSImageTestUtil {
       File... files) throws Exception
   {
     Map<File, String> md5s = getFileMD5s(files);
-    if (Sets.newHashSet(md5s.values()).size() != expectedUniqueHashes) {
+    int uniqueHashes = new HashSet<>(md5s.values()).size();
+    if (uniqueHashes != expectedUniqueHashes) {
       fail("Expected " + expectedUniqueHashes + " different hashes, got:\n  " +
           Joiner.on("\n  ")
             .withKeyValueSeparator("=")

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFsck.java

@@ -50,6 +50,7 @@ import java.security.PrivilegedExceptionAction;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
@@ -118,7 +119,6 @@ import org.apache.hadoop.net.NetworkTopology;
 import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.apache.hadoop.util.Sets;
 import org.apache.hadoop.util.ToolRunner;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
@@ -386,15 +386,15 @@ public class TestFsck {
                                         cluster.getNameNodePort()), conf);
     String[] fileNames = util.getFileNames(topDir);
     CorruptedTestFile[] ctFiles = new CorruptedTestFile[]{
-        new CorruptedTestFile(fileNames[0], Sets.newHashSet(0),
+        new CorruptedTestFile(fileNames[0], new HashSet<>(Arrays.asList(0)),
             dfsClient, numDatanodes, dfsBlockSize),
-        new CorruptedTestFile(fileNames[1], Sets.newHashSet(2, 3),
+        new CorruptedTestFile(fileNames[1], new HashSet<>(Arrays.asList(2, 3)),
             dfsClient, numDatanodes, dfsBlockSize),
-        new CorruptedTestFile(fileNames[2], Sets.newHashSet(4),
+        new CorruptedTestFile(fileNames[2], new HashSet<>(Arrays.asList(4)),
             dfsClient, numDatanodes, dfsBlockSize),
-        new CorruptedTestFile(fileNames[3], Sets.newHashSet(0, 1, 2, 3),
+        new CorruptedTestFile(fileNames[3], new HashSet<>(Arrays.asList(0, 1, 2, 3)),
             dfsClient, numDatanodes, dfsBlockSize),
-        new CorruptedTestFile(fileNames[4], Sets.newHashSet(1, 2, 3, 4),
+        new CorruptedTestFile(fileNames[4], new HashSet<>(Arrays.asList(1, 2, 3, 4)),
             dfsClient, numDatanodes, dfsBlockSize)
     };
     int totalMissingBlocks = 0;
@@ -2215,7 +2215,7 @@ public class TestFsck {
         new InetSocketAddress("localhost", cluster.getNameNodePort()), conf);
     final String blockFileToCorrupt = fileNames[0];
     final CorruptedTestFile ctf = new CorruptedTestFile(blockFileToCorrupt,
-        Sets.newHashSet(0), dfsClient, numDatanodes, dfsBlockSize);
+        new HashSet<>(Arrays.asList(0)), dfsClient, numDatanodes, dfsBlockSize);
     ctf.corruptBlocks(cluster);
 
     // Wait for fsck to discover all the missing blocks

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRecovery.java

@@ -28,6 +28,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
@@ -49,7 +50,6 @@ import org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeDirType;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.PathUtils;
-import org.apache.hadoop.util.Sets;
 import org.apache.hadoop.util.StringUtils;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -299,7 +299,7 @@ public class TestNameNodeRecovery {
 
     @Override
     public Set<Long> getValidTxIds() {
-      return Sets.newHashSet(0L);
+      return new HashSet<>(Arrays.asList(0L));
     } 
     
     public int getMaxOpSize() {
@@ -341,7 +341,7 @@ public class TestNameNodeRecovery {
 
     @Override
     public Set<Long> getValidTxIds() {
-      return Sets.newHashSet(0L);
+      return new HashSet<>(Arrays.asList(0L));
     } 
   }
 
@@ -387,7 +387,7 @@ public class TestNameNodeRecovery {
 
     @Override
     public Set<Long> getValidTxIds() {
-      return Sets.newHashSet(1L , 2L, 3L, 5L, 6L, 7L, 8L, 9L, 10L);
+      return new HashSet<>(Arrays.asList(1L, 2L, 3L, 5L, 6L, 7L, 8L, 9L, 10L));
     }
   }
   

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/security/TestRefreshUserMappings.java

@@ -34,6 +34,8 @@ import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
@@ -47,7 +49,6 @@ import org.apache.hadoop.security.authorize.AuthorizationException;
 import org.apache.hadoop.security.authorize.DefaultImpersonationProvider;
 import org.apache.hadoop.security.authorize.ProxyUsers;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.apache.hadoop.util.Sets;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.slf4j.event.Level;
@@ -93,7 +94,7 @@ public class TestRefreshUserMappings {
       LOG.info("Getting groups in MockUnixGroupsMapping");
       String g1 = user + (10 * i + 1);
       String g2 = user + (10 * i + 2);
-      Set<String> s = Sets.newHashSet(g1, g2);
+      Set<String> s = new HashSet<>(Arrays.asList(g1, g2));
       i++;
       return s;
     }