Intermittent failure of NodeMoveAPITest.testConcurrency

java.lang.AssertionError: Should have only found x once
	at org.testng.AssertJUnit.fail(AssertJUnit.java:57)
	at org.testng.AssertJUnit.assertTrue(AssertJUnit.java:22)
	at org.testng.AssertJUnit.assertFalse(AssertJUnit.java:39)
	at org.infinispan.api.tree.NodeMoveAPITest.testConcurrency(NodeMoveAPITest.java:405)
	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:74)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:673)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:846)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1170)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
	at org.testng.TestRunner.runWorkers(TestRunner.java:1147)
	at org.testng.TestRunner.privateRun(TestRunner.java:749)
	at org.testng.TestRunner.run(TestRunner.java:600)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:317)
	at org.testng.SuiteRunner.access$000(SuiteRunner.java:34)
	at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:351)
	at org.testng.internal.thread.ThreadUtil$CountDownLatchedRunnable.run(ThreadUtil.java:147)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)

2012-12-05 10:21:34,463 FATAL [NodeMoveAPITest] (testng-NodeMoveAPITest) Tree: 

+ /  {}
  + b/  {}
    + x/  {}
  + a/  {}
  + e/  {}
  + c/  {}
    + x/  {}
    + y/  {}
  + d/  {}

2012-12-05 10:21:34,464 ERROR [UnitTestTestNGListener] (testng-NodeMoveAPITest) Method testConcurrency(org.infinispan.api.tree.NodeMoveAPITest) threw an exception
java.lang.AssertionError: Should have only found x once
	at org.testng.AssertJUnit.fail(AssertJUnit.java:57)
	at org.testng.AssertJUnit.assertTrue(AssertJUnit.java:22)
	at org.testng.AssertJUnit.assertFalse(AssertJUnit.java:39)
	at org.infinispan.api.tree.NodeMoveAPITest.testConcurrency(NodeMoveAPITest.java:405)
	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:74)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:673)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:846)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1170)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
	at org.testng.TestRunner.runWorkers(TestRunner.java:1147)
	at org.testng.TestRunner.privateRun(TestRunner.java:749)
	at org.testng.TestRunner.run(TestRunner.java:600)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:317)
	at org.testng.SuiteRunner.access$000(SuiteRunner.java:34)
	at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:351)
	at org.testng.internal.thread.ThreadUtil$CountDownLatchedRunnable.run(ThreadUtil.java:147)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
[testng-NodeMoveAPITest] Test testConcurrency(org.infinispan.api.tree.NodeMoveAPITest) failed.
2012-12-05 10:21:34,466 ERROR [UnitTestTestNGListener] (testng-NodeMoveAPITest) Test failed testConcurrency(org.infinispan.api.tree.NodeMoveAPITest)
java.lang.AssertionError: Should have only found x once
	at org.testng.AssertJUnit.fail(AssertJUnit.java:57)
	at org.testng.AssertJUnit.assertTrue(AssertJUnit.java:22)
	at org.testng.AssertJUnit.assertFalse(AssertJUnit.java:39)
	at org.infinispan.api.tree.NodeMoveAPITest.testConcurrency(NodeMoveAPITest.java:405)
	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:74)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:673)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:846)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1170)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
	at org.testng.TestRunner.runWorkers(TestRunner.java:1147)
	at org.testng.TestRunner.privateRun(TestRunner.java:749)
	at org.testng.TestRunner.run(TestRunner.java:600)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:317)
	at org.testng.SuiteRunner.access$000(SuiteRunner.java:34)
	at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:351)
	at org.testng.internal.thread.ThreadUtil$CountDownLatchedRunnable.run(ThreadUtil.java:147)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)