java.util.ConcurrentModificationException
   at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:819)
   at java.util.ArrayList$Itr.next(ArrayList.java:791)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.ui.result.BugTree.createRootTreeNode(BugTree.java:141)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.ui.result.BugTree.access$500(BugTree.java:43)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.ui.result.BugTree$1.run(BugTree.java:91)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.util.ConcurrentModificationException
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:425)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.ui.result.BugTree.refresh(BugTree.java:89)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.ui.result.BugTree$SessionListener.propertyChange(BugTree.java:209)
   at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
   at org.nbheaven.sqe.codedefects.core.spi.AbstractQualitySession.fireResultChanged(AbstractQualitySession.java:95)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.CheckstyleSession.setResult(CheckstyleSession.java:100)
   at org.nbheaven.sqe.tools.checkstyle.codedefects.core.CheckstyleProjectScannerJob.postScan(CheckstyleProjectScannerJob.java:50)
   at org.nbheaven.sqe.codedefects.core.spi.SQECodedefectScanner$Job.run(SQECodedefectScanner.java:56)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1973)