JShell: jdk/jshell/UserInputTest.java failed in testReadInput() because the actual is not equal to the expected value

This test failed once with the following message:
----------System.out:(59/3293)----------
[TestNG] Running:
  jdk/jshell/UserInputTest.java

config KullaTesting.setUp(): success
test UserInputTest.testClose(): success
config KullaTesting.tearDown(): success
config KullaTesting.setUp(): success
test UserInputTest.testException(): success
config KullaTesting.tearDown(): success
config KullaTesting.setUp(): success
test UserInputTest.testReadInput(): failure
java.lang.AssertionError: Expected execution value of: 67, but got: 66 expected [67] but found [66]
at org.testng.Assert.fail(Assert.java:94)
at org.testng.Assert.failNotEquals(Assert.java:496)
at org.testng.Assert.assertEquals(Assert.java:125)
at org.testng.Assert.assertEquals(Assert.java:178)
at KullaTesting.checkEvents(KullaTesting.java:567)
at KullaTesting.assertEval(KullaTesting.java:384)
at KullaTesting.assertEval(KullaTesting.java:378)
at KullaTesting.assertEval(KullaTesting.java:353)
at UserInputTest.testReadInput(UserInputTest.java:44)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:537)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:821)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1131)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:124)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
at org.testng.TestRunner.privateRun(TestRunner.java:773)
at org.testng.TestRunner.run(TestRunner.java:623)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:352)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:310)
at org.testng.SuiteRunner.run(SuiteRunner.java:259)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1185)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1110)
at org.testng.TestNG.run(TestNG.java:1018)
at com.sun.javatest.regtest.TestNGAction$TestNGRunner.main(TestNGAction.java:220)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:537)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:226)
at java.base/java.lang.Thread.run(Thread.java:844)
config KullaTesting.tearDown(): success
config KullaTesting.setUp(): success
test UserInputTest.testScanner(): success
config KullaTesting.tearDown(): success

===============================================
jdk/jshell/UserInputTest.java
Total tests run: 4, Failures: 1, Skips: 0
===============================================

----------System.err:(12/721)----------
java.lang.Exception: failures: 1
at com.sun.javatest.regtest.TestNGAction$TestNGRunner.main(TestNGAction.java:223)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:537)
at com.sun.javatest.regtest.agent.MainActionHelper$SameVMRunnable.run(MainActionHelper.java:226)
at java.base/java.lang.Thread.run(Thread.java:844)

JavaTest Message: Test threw exception: java.lang.Exception
JavaTest Message: shutting down test

result: Failed. Execution failed: `main' threw exception: java.lang.Exception: failures: 1