AsyncStoreStressTest is broken

testReadWriteRemove(org.infinispan.stress.AsyncStoreStressTest)  Time elapsed: 72.377 sec  <<< FAILURE!
java.lang.UnsupportedOperationException
	at java.util.AbstractMap$SimpleImmutableEntry.setValue(AbstractMap.java:726)
	at org.infinispan.stress.AsyncStoreStressTest.testReadWriteRemove(AsyncStoreStressTest.java:140)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
	at org.testng.TestRunner.privateRun(TestRunner.java:767)
	at org.testng.TestRunner.run(TestRunner.java:617)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
	at org.testng.SuiteRunner.access$000(SuiteRunner.java:37)
	at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:368)
	at org.testng.internal.thread.ThreadUtil$2.call(ThreadUtil.java:64)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
	at java.lang.Thread.run(Thread.java:662)