The following NullPointerException was noticed in a personal CI job run of the AltServiceUsageTest:

java.lang.NullPointerException: Cannot invoke "java.nio.channels.DatagramChannel.close()" because "this.udpNotResponding" is null
    at AltServiceUsageTest.afterClass(AltServiceUsageTest.java:126)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
    at java.base/java.lang.reflect.Method.invoke(Method.java:565)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
    at org.testng.internal.MethodInvocationHelper.invokeMethodConsideringTimeout(MethodInvocationHelper.java:61)
    at org.testng.internal.ConfigInvoker.invokeConfigurationMethod(ConfigInvoker.java:366)
    at org.testng.internal.ConfigInvoker.invokeConfigurations(ConfigInvoker.java:320)
    at org.testng.internal.TestMethodWorker.invokeAfterClassMethods(TestMethodWorker.java:217)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:130)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
    at org.testng.TestRunner.privateRun(TestRunner.java:764)
    at org.testng.TestRunner.run(TestRunner.java:585)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
    at org.testng.SuiteRunner.run(SuiteRunner.java:286)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
    at org.testng.TestNG.runSuites(TestNG.java:1069)
    at org.testng.TestNG.run(TestNG.java:1037)
    at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:109)
    at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:65)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
    at java.base/java.lang.reflect.Method.invoke(Method.java:565)
    at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
    at java.base/java.lang.Thread.run(Thread.java:1474)