Making test less flakily fail

[java-codehunger]

Description

This test is flakily fails. I run this test many times and it makes assertion fails.

Related Issue

I was running this test many times and it fails. The failure message is.

Failure:
java.lang.AssertionError
at org.junit.Assert.fail(Assert.java:86)
at org.junit.Assert.assertTrue(Assert.java:41)
at org.junit.Assert.assertTrue(Assert.java:52)
at org.java_websocket.issues.Issue997Test.test_localServer_ServerLocalhost_ClientLocalhost_CheckInactive(Issue997Test.java:102)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.lang.Thread.run(Thread.java:750)

Results :

Failed tests: test_localServer_ServerLocalhost_ClientLocalhost_CheckInactive(org.java_websocket.issues.Issue997Test)

Tests run: 1, Failures: 1, Errors: 0, Skipped: 0

Motivation and Context

It will reduce the chances of flaky failure.

How Has This Been Tested?

I run the test in Ubuntu 20 with JDK both 8 and 11.

Types of changes

• I simply add a little wait time before the assertion checking.

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.