java.lang.AssertionError
        at com.sun.tools.javac.comp.Enter.shadowTypeEnvs(Enter.java:250)
        at com.sun.tools.javac.api.JavacTrees.attribStatToTree(JavacTrees.java:297)
        at com.sun.tools.javac.api.JavacTrees.getAttrContext(JavacTrees.java:274)
        at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:192)
        at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:84)
        at org.netbeans.modules.debugger.jpda.projects.AST2Bytecode.matchSourceTree2Bytecode(AST2Bytecode.java:194)
        at org.netbeans.modules.debugger.jpda.projects.EditorContextImpl.getOperations(EditorContextImpl.java:1186)
        at org.netbeans.modules.debugger.jpda.ExpressionPool.createExpressionAt(ExpressionPool.java:170)
        at org.netbeans.modules.debugger.jpda.ExpressionPool.getExpressionAt(ExpressionPool.java:87)
        at org.netbeans.modules.debugger.jpda.actions.MethodChooser.collectOperations(MethodChooser.java:293)
        at org.netbeans.modules.debugger.jpda.actions.MethodChooser.run(MethodChooser.java:185)
        at org.netbeans.modules.debugger.jpda.actions.StepIntoActionProvider.doMethodSelection(StepIntoActionProvider.java:169)
        at org.netbeans.modules.debugger.jpda.actions.StepIntoActionProvider.runAction(StepIntoActionProvider.java:113)
        at org.netbeans.modules.debugger.jpda.actions.StepIntoActionProvider$1.run(StepIntoActionProvider.java:104)
        at org.netbeans.modules.debugger.jpda.actions.JPDADebuggerActionProvider$1.run(JPDADebuggerActionProvider.java:176)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)