#6 error in combo box demo 2

[Russell Seidel]

This error came up while analyzing the ComboBoxDemo2 Swing Tutorial. This error is different than the one that came up in ComboBoxDemo, which I think is weird because they pretty much do the same thing.

null
Error
Fri Nov 18 20:57:24 EST 2011
CriticAL framework encountered a problem while analyzing:
[Class: test.ComboBoxDemo2]
[Method: <test.comboboxdemo2: void="" \<init="">()>]</test.comboboxdemo2:>
[Line Number: 99]

java.lang.NullPointerException
at edu.clarkson.serl.critic.interpreter.AbstractSymbol.notifyAdded(AbstractSymbol.java:503)
at edu.clarkson.serl.critic.adt.ClosedList.add(ClosedList.java:89)
at edu.clarkson.serl.critic.swing.types.JComponentAbstraction.add(JComponentAbstraction.java:734)
at edu.clarkson.serl.critic.swing.types.JComponentAbstraction.execute(JComponentAbstraction.java:142)
at edu.clarkson.serl.critic.swing.types.JPanelAbstraction.execute(JPanelAbstraction.java:72)
at edu.clarkson.serl.critic.interpreter.model.InvokeInstance.execute(InvokeInstance.java:62)
at edu.clarkson.serl.critic.interpreter.model.StmtInvoke.executeStmt(StmtInvoke.java:59)
at edu.clarkson.serl.critic.interpreter.model.StmtAbstract.execute(StmtAbstract.java:111)
at edu.clarkson.serl.critic.interpreter.Interpreter.processContext(Interpreter.java:373)
at edu.clarkson.serl.critic.interpreter.Interpreter.execute(Interpreter.java:284)
at edu.clarkson.serl.critic.jobs.internal.CriticMainJob.run(CriticMainJob.java:86)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)