MINOR: Fix some typos for core (#13882)

Reviewers:  Divij Vaidya <diviv@amazon.com>

core/src/main/scala/kafka/admin/TopicCommand.scala

@@ -462,7 +462,7 @@ object TopicCommand extends Logging {
 
   private def getReplicationFactor(tpi: TopicPartitionInfo, reassignment: Option[PartitionReassignment]): Int = {
     // It is possible for a reassignment to complete between the time we have fetched its state and the time
-    // we fetch partition metadata. In ths case, we ignore the reassignment when determining replication factor.
+    // we fetch partition metadata. In this case, we ignore the reassignment when determining replication factor.
     def isReassignmentInProgress(ra: PartitionReassignment): Boolean = {
       // Reassignment is still in progress as long as the removing and adding replicas are still present
       val allReplicaIds = tpi.replicas.asScala.map(_.id).toSet

core/src/main/scala/kafka/controller/ControllerChannelManager.scala

@@ -361,7 +361,7 @@ class ControllerBrokerRequestBatch(
  * @param metadataProvider Provider to provide the relevant metadata to build the state needed to
  *                         send RPCs
  * @param metadataVersionProvider Provider to provide the metadata version used by the controller.
- * @param stateChangeLogger logger to log the various events while sending requests and receving
+ * @param stateChangeLogger logger to log the various events while sending requests and receiving
  *                          responses from the brokers
  * @param kraftController whether the controller is KRaft controller
  */

core/src/main/scala/kafka/raft/RaftManager.scala

@@ -152,7 +152,7 @@ class KafkaRaftManager[T](
   private val dataDir = createDataDir()
 
   private val dataDirLock = {
-    // Aquire the log dir lock if the metadata log dir is different from the log dirs
+    // Acquire the log dir lock if the metadata log dir is different from the log dirs
     val differentMetadataLogDir = !config
       .logDirs
       .map(Paths.get(_).toAbsolutePath)

core/src/main/scala/kafka/server/ForwardingManager.scala

@@ -63,7 +63,7 @@ trait ForwardingManager {
    *                            byte buffer from the envelope request, since we will be mutating
    *                            the position and limit fields. It should be a copy.
    * @param requestBody         The AbstractRequest we are sending.
-   * @param requestToString     A callback which can be invoked to produce a human-readable decription
+   * @param requestToString     A callback which can be invoked to produce a human-readable description
    *                            of the request.
    * @param responseCallback    A callback which takes in an `Option[AbstractResponse]`.
    *                            We will call this function with Some(x) after the controller responds with x.

core/src/main/scala/kafka/server/KafkaConfig.scala

@@ -1134,7 +1134,7 @@ object KafkaConfig {
   val DelegationTokenSecretKeyDoc = "Secret key to generate and verify delegation tokens. The same key must be configured across all the brokers. " +
     " If the key is not set or set to empty string, brokers will disable the delegation token support."
   val DelegationTokenMaxLifeTimeDoc = "The token has a maximum lifetime beyond which it cannot be renewed anymore. Default value 7 days."
-  val DelegationTokenExpiryTimeMsDoc = "The token validity time in miliseconds before the token needs to be renewed. Default value 1 day."
+  val DelegationTokenExpiryTimeMsDoc = "The token validity time in milliseconds before the token needs to be renewed. Default value 1 day."
   val DelegationTokenExpiryCheckIntervalDoc = "Scan interval to remove expired delegation tokens."
 
   /** ********* Password encryption configuration for dynamic configs *********/

core/src/main/scala/kafka/zk/KafkaZkClient.scala

@@ -275,7 +275,7 @@ class KafkaZkClient private[zk] (zooKeeperClient: ZooKeeperClient, isSecure: Boo
 
   /**
    * Gets topic partition states for the given partitions.
-   * @param partitions the partitions for which we want ot get states.
+   * @param partitions the partitions for which we want to get states.
    * @return sequence of GetDataResponses whose contexts are the partitions they are associated with.
    */
   def getTopicPartitionStatesRaw(partitions: Seq[TopicPartition]): Seq[GetDataResponse] = {
@@ -599,7 +599,7 @@ class KafkaZkClient private[zk] (zooKeeperClient: ZooKeeperClient, isSecure: Boo
   /**
    * Adds a topic ID to existing topic and replica assignments
    * @param topicIdReplicaAssignments the TopicIDReplicaAssignments to add a topic ID to
-   * @return the updated TopicIdReplicaAssigments including the newly created topic IDs
+   * @return the updated TopicIdReplicaAssignments including the newly created topic IDs
    */
   def setTopicIds(topicIdReplicaAssignments: collection.Set[TopicIdReplicaAssignment],
                   expectedControllerEpochZkVersion: Int): Set[TopicIdReplicaAssignment] = {

core/src/test/scala/integration/kafka/api/PlaintextConsumerTest.scala

@@ -266,7 +266,7 @@ class PlaintextConsumerTest extends BaseConsumerTest {
     consumer.subscribe(List(topic).asJava)
     awaitAssignment(consumer, Set(tp, tp2))
 
-    // should auto-commit seeked positions before closing
+    // should auto-commit sought positions before closing
     consumer.seek(tp, 300)
     consumer.seek(tp2, 500)
     consumer.close()
@@ -289,7 +289,7 @@ class PlaintextConsumerTest extends BaseConsumerTest {
     consumer.subscribe(List(topic).asJava)
     awaitAssignment(consumer, Set(tp, tp2))
 
-    // should auto-commit seeked positions before closing
+    // should auto-commit sought positions before closing
     consumer.seek(tp, 300)
     consumer.seek(tp2, 500)
 

core/src/test/scala/integration/kafka/server/DynamicBrokerReconfigurationTest.scala

@@ -376,7 +376,7 @@ class DynamicBrokerReconfigurationTest extends QuorumTestHarness with SaslSetup
 
     // Produce/consume should work with new truststore with new producer/consumer
     val producer = ProducerBuilder().trustStoreProps(sslProperties2).maxRetries(0).build()
-    // Start the new consumer in a separate group than the continous consumer started at the beginning of the test so
+    // Start the new consumer in a separate group than the continuous consumer started at the beginning of the test so
     // that it is not disrupted by rebalance.
     val consumer = ConsumerBuilder("group2").trustStoreProps(sslProperties2).topic(topic2).build()
     verifyProduceConsume(producer, consumer, 10, topic2)

core/src/test/scala/integration/kafka/server/RaftClusterSnapshotTest.scala

@@ -71,7 +71,7 @@ class RaftClusterSnapshotTest {
 
       assertEquals(numberOfControllers + numberOfBrokers, cluster.raftManagers.size())
 
-      // For every controller and broker perform some sanity checks against the lastest snapshot
+      // For every controller and broker perform some sanity checks against the latest snapshot
       for ((_, raftManager) <- cluster.raftManagers().asScala) {
         TestUtils.resource(
           RecordsSnapshotReader.of(

core/src/test/scala/other/kafka/TestLinearWriteSpeed.scala

@@ -145,16 +145,16 @@ object TestLinearWriteSpeed {
     while(totalWritten + bufferSize < bytesToWrite) {
       val start = System.nanoTime
       val writeSize = writables((count % numFiles).toInt.abs).write()
-      val ellapsed = System.nanoTime - start
+      val elapsed = System.nanoTime - start
-      maxLatency = max(ellapsed, maxLatency)
+      maxLatency = max(elapsed, maxLatency)
-      totalLatency += ellapsed
+      totalLatency += elapsed
       written += writeSize
       count += 1
       totalWritten += writeSize
       if((start - lastReport)/(1000.0*1000.0) > reportingInterval.doubleValue) {
-        val ellapsedSecs = (start - lastReport) / (1000.0*1000.0*1000.0)
+        val elapsedSecs = (start - lastReport) / (1000.0*1000.0*1000.0)
         val mb = written / (1024.0*1024.0)
-        println("%10.3f\t%10.3f\t%10.3f".format(mb / ellapsedSecs, totalLatency / count.toDouble / (1000.0*1000.0), maxLatency / (1000.0 * 1000.0)))
+        println("%10.3f\t%10.3f\t%10.3f".format(mb / elapsedSecs, totalLatency / count.toDouble / (1000.0*1000.0), maxLatency / (1000.0 * 1000.0)))
         lastReport = start
         written = 0
         maxLatency = 0L

core/src/test/scala/unit/kafka/admin/ConsumerGroupServiceTest.scala

@@ -76,8 +76,8 @@ class ConsumerGroupServiceTest {
     val testTopicPartition4 = new TopicPartition("testTopic2", 1);
     val testTopicPartition5 = new TopicPartition("testTopic2", 2);
 
-    // Some topic's partitions gets valid OffsetAndMetada values, other gets nulls values (negative integers) and others aren't defined
+    // Some topic's partitions gets valid OffsetAndMetadata values, other gets nulls values (negative integers) and others aren't defined
-    val commitedOffsets = Map(
+    val committedOffsets = Map(
       testTopicPartition1 -> new OffsetAndMetadata(100),
       testTopicPartition2 -> null,
       testTopicPartition3 -> new OffsetAndMetadata(100),
@@ -115,7 +115,7 @@ class ConsumerGroupServiceTest {
     when(admin.listConsumerGroupOffsets(ArgumentMatchers.eq(listConsumerGroupOffsetsSpec), any()))
       .thenReturn(
         AdminClientTestUtils.listConsumerGroupOffsetsResult(
-          Collections.singletonMap(group, commitedOffsets)))
+          Collections.singletonMap(group, committedOffsets)))
     when(admin.listOffsets(
       ArgumentMatchers.argThat(offsetsArgMatcher(assignedTopicPartitions)),
       any()

core/src/test/scala/unit/kafka/admin/ReassignPartitionsUnitTest.scala

@@ -224,9 +224,9 @@ class ReassignPartitionsUnitTest {
   @Test
   def testGetBrokerRackInformation(): Unit = {
     val adminClient = new MockAdminClient.Builder().
-      brokers(Arrays.asList(new Node(0, "locahost", 9092, "rack0"),
+      brokers(Arrays.asList(new Node(0, "localhost", 9092, "rack0"),
-        new Node(1, "locahost", 9093, "rack1"),
+        new Node(1, "localhost", 9093, "rack1"),
-        new Node(2, "locahost", 9094, null))).
+        new Node(2, "localhost", 9094, null))).
       build()
     try {
       assertEquals(Seq(
@@ -304,12 +304,12 @@ class ReassignPartitionsUnitTest {
   def testGenerateAssignmentWithInconsistentRacks(): Unit = {
     val adminClient = new MockAdminClient.Builder().
       brokers(Arrays.asList(
-        new Node(0, "locahost", 9092, "rack0"),
+        new Node(0, "localhost", 9092, "rack0"),
-        new Node(1, "locahost", 9093, "rack0"),
+        new Node(1, "localhost", 9093, "rack0"),
-        new Node(2, "locahost", 9094, null),
+        new Node(2, "localhost", 9094, null),
-        new Node(3, "locahost", 9095, "rack1"),
+        new Node(3, "localhost", 9095, "rack1"),
-        new Node(4, "locahost", 9096, "rack1"),
+        new Node(4, "localhost", 9096, "rack1"),
-        new Node(5, "locahost", 9097, "rack2"))).
+        new Node(5, "localhost", 9097, "rack2"))).
       build()
     try {
       addTopics(adminClient)

core/src/test/scala/unit/kafka/cluster/PartitionLockTest.scala

@@ -114,7 +114,7 @@ class PartitionLockTest extends Logging {
 
   /**
    * Verifies concurrent produce and replica fetch log read result update with ISR updates. This
-   * can result in delays in processing produce and replica fetch requets since write lock is obtained,
+   * can result in delays in processing produce and replica fetch requests since write lock is obtained,
    * but it should complete without any failures.
    */
   @Test

core/src/test/scala/unit/kafka/coordinator/group/GroupCoordinatorTest.scala

@@ -2263,13 +2263,13 @@ class GroupCoordinatorTest {
 
     assertEquals(Errors.NONE, await(leaderResult, 1).error)
 
-    // Leader should be able to heartbeart
+    // Leader should be able to heartbeat
     verifyHeartbeat(results.head, Errors.NONE)
 
     // Advance part the rebalance timeout to trigger the delayed operation.
     timer.advanceClock(DefaultRebalanceTimeout / 2 + 1)
 
-    // Leader should be able to heartbeart
+    // Leader should be able to heartbeat
     verifyHeartbeat(results.head, Errors.REBALANCE_IN_PROGRESS)
 
     // Followers should have been removed.
@@ -2347,7 +2347,7 @@ class GroupCoordinatorTest {
     val followerErrors = followerResults.map(await(_, 1).error)
     assertEquals(Set(Errors.NONE), followerErrors.toSet)
 
-    // Advance past the rebalance timeout to expire the Sync timout. All
+    // Advance past the rebalance timeout to expire the Sync timeout. All
     // members should remain and the group should not rebalance.
     timer.advanceClock(DefaultRebalanceTimeout / 2 + 1)
 

core/src/test/scala/unit/kafka/coordinator/group/GroupMetadataTest.scala

@@ -799,7 +799,7 @@ class GroupMetadataTest {
     assertTrue(group.has(memberId))
     assertTrue(group.hasStaticMember(groupInstanceId))
 
-    // We aren ot permitted to add the member again if it is already present
+    // We are not permitted to add the member again if it is already present
     assertThrows(classOf[IllegalStateException], () => group.add(member))
   }
 

core/src/test/scala/unit/kafka/coordinator/transaction/TransactionMarkerRequestCompletionHandlerTest.scala

@@ -123,7 +123,7 @@ class TransactionMarkerRequestCompletionHandlerTest {
   }
 
   @Test
-  def shouldCompleteDelayedOperationWheCoordinatorEpochFenced(): Unit = {
+  def shouldCompleteDelayedOperationWhenCoordinatorEpochFenced(): Unit = {
     mockCache()
 
     verifyRemoveDelayedOperationOnError(Errors.TRANSACTION_COORDINATOR_FENCED)

core/src/test/scala/unit/kafka/coordinator/transaction/TransactionStateManagerTest.scala

@@ -771,7 +771,7 @@ class TransactionStateManagerTest {
 
     loadTransactionsForPartitions(partitionIds)
 
-    // When TransactionMetadata is intialized for the first time, it has the following
+    // When TransactionMetadata is initialized for the first time, it has the following
     // shape. Then, the producer id and producer epoch are initialized and we try to
     // write the change. If the write fails (e.g. under min isr), the TransactionMetadata
     // is left at it is. If the transactional id is never reused, the TransactionMetadata

core/src/test/scala/unit/kafka/integration/MinIsrConfigTest.scala

@@ -32,7 +32,7 @@ class MinIsrConfigTest extends KafkaServerTestHarness {
 
   @ParameterizedTest(name = TestInfoUtils.TestWithParameterizedQuorumName)
   @ValueSource(strings = Array("zk", "kraft"))
-  def testDeaultKafkaConfig(quorum: String): Unit = {
+  def testDefaultKafkaConfig(quorum: String): Unit = {
     assert(brokers.head.logManager.initialDefaultConfig.minInSyncReplicas == 5)
   }
 }

core/src/test/scala/unit/kafka/log/OffsetMapTest.scala

@@ -81,8 +81,8 @@ object OffsetMapTest {
     val load = args(1).toDouble
     val start = System.nanoTime
     val map = test.validateMap(size, load)
-    val ellapsedMs = (System.nanoTime - start) / 1000.0 / 1000.0
+    val elapsedMs = (System.nanoTime - start) / 1000.0 / 1000.0
-    println(s"${map.size} entries in map of size ${map.slots} in $ellapsedMs ms")
+    println(s"${map.size} entries in map of size ${map.slots} in $elapsedMs ms")
     println("Collision rate: %.1f%%".format(100*map.collisionRate))
   }
 }

core/src/test/scala/unit/kafka/log/TimeIndexTest.scala

@@ -34,7 +34,7 @@ class TimeIndexTest {
 
   @BeforeEach
   def setup(): Unit = {
-    this.idx = new TimeIndex(nonExistantTempFile(), baseOffset, maxEntries * 12)
+    this.idx = new TimeIndex(nonExistentTempFile(), baseOffset, maxEntries * 12)
   }
 
   @AfterEach
@@ -97,7 +97,7 @@ class TimeIndexTest {
       idx.maybeAppend(i * 10, i * 10 + baseOffset)
   }
 
-  def nonExistantTempFile(): File = {
+  def nonExistentTempFile(): File = {
     val file = TestUtils.tempFile()
     file.delete()
     file

core/src/test/scala/unit/kafka/security/authorizer/AuthorizerTest.scala

@@ -515,7 +515,7 @@ class AuthorizerTest extends QuorumTestHarness with BaseAuthorizerTest {
     }
 
     // Alternate authorizer, Remove all acls that end in 0
-    val concurrentFuctions = acls.map { case (acl, aclId) =>
+    val concurrentFunctions = acls.map { case (acl, aclId) =>
       () => {
         if (aclId % 2 == 0) {
           addAcls(authorizer1, Set(acl), commonResource)
@@ -532,7 +532,7 @@ class AuthorizerTest extends QuorumTestHarness with BaseAuthorizerTest {
       aclId % 10 != 0
     }.map(_._1).toSet
 
-    TestUtils.assertConcurrent("Should support many concurrent calls", concurrentFuctions, 30 * 1000)
+    TestUtils.assertConcurrent("Should support many concurrent calls", concurrentFunctions, 30 * 1000)
 
     TestUtils.waitAndVerifyAcls(expectedAcls, authorizer1, commonResource)
     TestUtils.waitAndVerifyAcls(expectedAcls, authorizer2, commonResource)
@@ -595,14 +595,14 @@ class AuthorizerTest extends QuorumTestHarness with BaseAuthorizerTest {
     val acl = new AccessControlEntry(new KafkaPrincipal(KafkaPrincipal.USER_TYPE, username).toString, WildcardHost, AclOperation.ALL, ALLOW)
 
     // Alternate authorizer to keep adding and removing ZooKeeper path
-    val concurrentFuctions = (0 to 50).map { _ =>
+    val concurrentFunctions = (0 to 50).map { _ =>
       () => {
         addAcls(authorizer1, Set(acl), resource)
         removeAcls(authorizer2, Set(acl), resource)
       }
     }
 
-    TestUtils.assertConcurrent("Should support many concurrent calls", concurrentFuctions, 30 * 1000)
+    TestUtils.assertConcurrent("Should support many concurrent calls", concurrentFunctions, 30 * 1000)
 
     TestUtils.waitAndVerifyAcls(Set.empty[AccessControlEntry], authorizer1, resource)
     TestUtils.waitAndVerifyAcls(Set.empty[AccessControlEntry], authorizer2, resource)

core/src/test/scala/unit/kafka/server/AlterUserScramCredentialsRequestTest.scala

@@ -286,7 +286,7 @@ class AlterUserScramCredentialsRequestTest extends BaseRequestTest {
     checkUserAppearsInAlterResults(results1_1, user2)
 
     // KRaft is eventually consistent so it is possible to call describe before 
-    // the credential is propogated from the controller to the broker.
+    // the credential is propagated from the controller to the broker.
     TestUtils.waitUntilTrue(() => describeAllWithNoTopLevelErrorConfirmed().data.results.size == 2,
                                "describeAllWithNoTopLevelErrorConfirmed does not see 2 users");
 

core/src/test/scala/unit/kafka/server/CreateTopicsRequestWithPolicyTest.scala

@@ -159,7 +159,7 @@ object CreateTopicsRequestWithPolicyTest {
       if (numPartitions != null || replicationFactor != null) {
         require(numPartitions != null, s"numPartitions should not be null, but it is $numPartitions")
         require(replicationFactor != null, s"replicationFactor should not be null, but it is $replicationFactor")
-        require(replicasAssignments == null, s"replicaAssigments should be null, but it is $replicasAssignments")
+        require(replicasAssignments == null, s"replicaAssignments should be null, but it is $replicasAssignments")
 
         if (numPartitions < 5)
           throw new PolicyViolationException(s"Topics should have at least 5 partitions, received $numPartitions")
@@ -173,7 +173,7 @@ object CreateTopicsRequestWithPolicyTest {
       } else {
         require(numPartitions == null, s"numPartitions should be null, but it is $numPartitions")
         require(replicationFactor == null, s"replicationFactor should be null, but it is $replicationFactor")
-        require(replicasAssignments != null, s"replicaAssigments should not be null, but it is $replicasAssignments")
+        require(replicasAssignments != null, s"replicaAssignments should not be null, but it is $replicasAssignments")
 
         replicasAssignments.asScala.toSeq.sortBy { case (tp, _) => tp }.foreach { case (partitionId, assignment) =>
           if (assignment.size < 2)

core/src/test/scala/unit/kafka/server/ZkAdminManagerTest.scala

@@ -59,7 +59,7 @@ class ZkAdminManagerTest {
     assertEquals(1, oneProp.size)
     assertEquals(1234.0, oneProp("foo"))
 
-    // This is probably not desired, but kept for compatability with existing usages
+    // This is probably not desired, but kept for compatibility with existing usages
     val emptyKey = ZkAdminManager.clientQuotaPropsToDoubleMap(Map("" -> "-42.1"))
     assertEquals(1, emptyKey.size)
     assertEquals(-42.1, emptyKey(""))

core/src/test/scala/unit/kafka/server/checkpoints/InMemoryLeaderEpochCheckpointTest.scala

@@ -48,9 +48,9 @@ class InMemoryLeaderEpochCheckpointTest {
     val epochs = java.util.Arrays.asList(new EpochEntry(expectedEpoch, expectedStartOffset))
     checkpoint.write(epochs)
     assertEquals(epochs, checkpoint.read())
-    val ba = checkpoint.readAsByteBuffer()
+    val buffer = checkpoint.readAsByteBuffer()
 
-    val bufferedReader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(ba.array()), StandardCharsets.UTF_8))
+    val bufferedReader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(buffer.array()), StandardCharsets.UTF_8))
     assertEquals(expectedVersion.toString, bufferedReader.readLine())
     assertEquals(epochs.size().toString, bufferedReader.readLine())
     assertEquals(s"$expectedEpoch $expectedStartOffset", bufferedReader.readLine())

core/src/test/scala/unit/kafka/server/epoch/LeaderEpochFileCacheTest.scala

@@ -92,7 +92,7 @@ class LeaderEpochFileCacheTest {
     cache.assign(2, 11)
     cache.assign(3, 12)
 
-    //When (say a bootstraping follower) sends request for UNDEFINED_EPOCH
+    //When (say a bootstrapping follower) sends request for UNDEFINED_EPOCH
     val epochAndOffsetFor = toTuple(cache.endOffsetFor(UNDEFINED_EPOCH, 0L))
 
     //Then

core/src/test/scala/unit/kafka/zk/KafkaZkClientTest.scala

@@ -1188,7 +1188,7 @@ class KafkaZkClientTest extends QuorumTestHarness {
 
     assertEquals(CreateResponse(Code.NODEEXISTS, ControllerEpochZNode.path, None, null, ResponseMetadata(0, 0)),
       eraseMetadata(zkClient.createControllerEpochRaw(0)),
-      "Attemt to create existing nodes should return NODEEXISTS")
+      "Attempt to create existing nodes should return NODEEXISTS")
 
     assertEquals(SetDataResponse(Code.OK, ControllerEpochZNode.path, None, statWithVersion(1), ResponseMetadata(0, 0)),
       eraseMetadataAndStat(zkClient.setControllerEpochRaw(1, 0)),
@@ -1414,7 +1414,7 @@ class KafkaZkClientTest extends QuorumTestHarness {
   }
 
   @Test
-  def testJuteMaxBufffer(): Unit = {
+  def testJuteMaxBuffer(): Unit = {
 
     def assertJuteMaxBufferConfig(clientConfig: ZKClientConfig, expectedValue: String): Unit = {
       val client = KafkaZkClient(zkConnect, zkAclsEnabled.getOrElse(JaasUtils.isZkSaslEnabled), zkSessionTimeout,

core/src/test/scala/unit/kafka/zk/migration/ZkConfigMigrationClientTest.scala

@@ -73,7 +73,7 @@ class ZkConfigMigrationClientTest extends ZkMigrationTestHarness {
       val value = message.value
 
       assertTrue(props.containsKey(name))
-      // If the config is senstive, compare it to the decoded value.
+      // If the config is sensitive, compare it to the decoded value.
       if (name == KafkaConfig.SslKeystorePasswordProp) {
         assertEquals(SECRET, value)
       } else {

group-coordinator/src/test/java/org/apache/kafka/coordinator/group/generic/GenericGroupTest.java

@@ -757,7 +757,7 @@ public class GenericGroupTest {
         assertTrue(group.hasMemberId(memberId));
         assertTrue(group.hasStaticMember(groupInstanceId));
 
-        // We aren ot permitted to add the member again if it is already present
+        // We are not permitted to add the member again if it is already present
         assertThrows(IllegalStateException.class, () -> group.add(member));
     }