java/util/concurrent/ConcurrentHashMap/WhiteBox.java fails with jtreg 6

 java/util/concurrent/ConcurrentHashMap/WhiteBox.java fails with a TestNG assertion failure when run with jtreg 6, which provides TestNG 7.4.0.

The output to System.out is

test WhiteBox.constructorsShouldGiveSameInitialCapacity(): success
test WhiteBox.defaultConstructor(): success
test WhiteBox.shouldNotResizeWhenInitialCapacityProvided(): success
test WhiteBox.testSerialization(): failure
java.lang.AssertionError: expected not same [{}] but found [{}]
at org.testng.Assert.fail(Assert.java:99)
at org.testng.Assert.failSame(Assert.java:1025)
at org.testng.Assert.assertNotSame(Assert.java:1005)
at org.testng.Assert.assertNotSame(Assert.java:1017)
at WhiteBox.serialClone(WhiteBox.java:178)
at WhiteBox.testSerialization(WhiteBox.java:188)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:133)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:598)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:173)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:824)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:146)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.testng.TestRunner.privateRun(TestRunner.java:794)
at org.testng.TestRunner.run(TestRunner.java:596)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:377)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:371)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:332)
at org.testng.SuiteRunner.run(SuiteRunner.java:276)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1212)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1134)
at org.testng.TestNG.runSuites(TestNG.java:1063)
at org.testng.TestNG.run(TestNG.java:1031)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:94)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:831)
test WhiteBox.testTableSizeFor(): success

===============================================
java/util/concurrent/ConcurrentHashMap/WhiteBox.java
Total tests run: 5, Passes: 4, Failures: 1, Skips: 0
===============================================