java.util.ConcurrentModificationException
	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:548)
	at java.util.LinkedList$ListItr.next(LinkedList.java:484)
	at org.netbeans.modules.java.JavaDataLoader$JavaFileEntry.delete(JavaDataLoader.java:408)
	at org.openide.loaders.MultiDataObject.handleDelete(MultiDataObject.java:445)
	at org.openide.loaders.DataObject$3.run(DataObject.java:532)
	at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:89)
	at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:414)
	at org.openide.loaders.DataObject.delete(DataObject.java:530)
	at org.netbeans.test.java.Utilities.delete(Utilities.java:43)
	at org.netbeans.test.java.gui.customizers.ClassCustomizer.testAddInterface(ClassCustomizer.java:160)
	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:324)
	at junit.framework.TestCase.runTest(TestCase.java:166)
	at junit.framework.TestCase.runBare(TestCase.java:140)
	at org.netbeans.jellytools.JellyTestCase.runBare(Unknown Source)
	at junit.framework.TestResult$1.protect(TestResult.java:106)
	at junit.framework.TestResult.runProtected(TestResult.java:124)
	at junit.framework.TestResult.run(TestResult.java:109)
	at junit.framework.TestCase.run(TestCase.java:131)
	at org.netbeans.junit.NbTestCase.run(NbTestCase.java:76)
	at junit.framework.TestSuite.runTest(TestSuite.java:173)
	at junit.framework.TestSuite.run(TestSuite.java:168)
	at org.netbeans.xtest.testrunner.JUnitTestRunner.runTests(JUnitTestRunner.java:156)
	at org.netbeans.xtest.testrunner.JUnitTestRunnerTask.executeInIDE(JUnitTestRunnerTask.java:299)
	at org.netbeans.xtest.testrunner.JUnitTestRunnerTask.executeTestRun(JUnitTestRunnerTask.java:432)
	at org.netbeans.xtest.testrunner.JUnitTestRunnerTask.execute(JUnitTestRunnerTask.java:117)
	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:166)
	at org.apache.tools.ant.Task.perform(Task.java:319)
	at org.apache.tools.ant.Target.execute(Target.java:309)
	at org.apache.tools.ant.Target.performTasks(Target.java:336)
	at org.apache.tools.ant.Project.executeTarget(Project.java:1306)
	at org.netbeans.xtest.AntRunner.run(AntRunner.java:76)
	at org.netbeans.xtest.AntRunner.main(AntRunner.java:27)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:324)
	at org.openide.execution.ThreadExecutor.executeClass(ThreadExecutor.java:116)
	at org.openide.execution.ThreadExecutor$TERunnable.run(ThreadExecutor.java:183)
	at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:118)