java.lang.NullPointerException at com.sun.tools.javac.comp.MemberEnter$Synthesizer.visit(MemberEnter.java:1707) at com.sun.tools.javac.comp.MemberEnter$9.getModelType(MemberEnter.java:1689) at com.sun.tools.javac.code.Symbol$ClassSymbol.getSuperclass(Symbol.java:1074) at com.sun.tools.javac.code.Types$20.visitClassType(Types.java:2312) at com.sun.tools.javac.code.Types$20.visitClassType(Types.java:2301) at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:763) at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:4511) at com.sun.tools.javac.code.Types.supertype(Types.java:2298) at com.sun.tools.javac.code.Types$15.visitClassType(Types.java:1957) at com.sun.tools.javac.code.Types$15.visitClassType(Types.java:1946) at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:763) at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4430) at com.sun.tools.javac.code.Types.asSuper(Types.java:1943) at com.sun.tools.javac.code.Types$6.visitClassType(Types.java:920) at com.sun.tools.javac.code.Types$6.visitClassType(Types.java:842) at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:763) at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4430) at com.sun.tools.javac.code.Types.isSubtype(Types.java:838) at com.sun.tools.javac.code.Types.isSubtype(Types.java:808) at com.sun.tools.javac.code.Types.isSubtypeUncheckedInternal(Types.java:761) at com.sun.tools.javac.code.Types.isSubtypeUnchecked(Types.java:745) at com.sun.tools.javac.comp.Resolve$MethodCheckContext.compatible(Resolve.java:944) at com.sun.tools.javac.comp.Check.checkType(Check.java:550) at com.sun.tools.javac.comp.Attr$ResultInfo.check(Attr.java:512) at com.sun.tools.javac.comp.Resolve$MethodResultInfo.check(Resolve.java:982) at com.sun.tools.javac.comp.Resolve$4.checkArg(Resolve.java:826) at com.sun.tools.javac.comp.Resolve$AbstractMethodCheck.argumentsAcceptable(Resolve.java:737) at com.sun.tools.javac.comp.Resolve$4.argumentsAcceptable(Resolve.java:835) at com.sun.tools.javac.comp.Resolve.rawInstantiate(Resolve.java:582) at com.sun.tools.javac.comp.Resolve.selectBest(Resolve.java:1422) at com.sun.tools.javac.comp.Resolve.findMethodInScope(Resolve.java:1601) at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1672) at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1645) at com.sun.tools.javac.comp.Resolve$14.doLookup(Resolve.java:2659) at com.sun.tools.javac.comp.Resolve$BasicLookupHelper.lookup(Resolve.java:3067) at com.sun.tools.javac.comp.Resolve.lookupMethod(Resolve.java:3318) at com.sun.tools.javac.comp.Resolve.resolveOperator(Resolve.java:2655) at com.sun.tools.javac.comp.Resolve.resolveBinaryOperator(Resolve.java:2696) at com.sun.tools.javac.comp.Attr.visitBinary(Attr.java:3153) at com.sun.tools.javac.tree.JCTree$JCBinary.accept(JCTree.java:1785) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:644) at com.sun.tools.javac.comp.Attr.visitConditional(Attr.java:1457) at com.sun.tools.javac.tree.JCTree$JCConditional.accept(JCTree.java:1237) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.visitParens(Attr.java:3068) at com.sun.tools.javac.tree.JCTree$JCParens.accept(JCTree.java:1661) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.visitBinary(Attr.java:3150) at com.sun.tools.javac.tree.JCTree$JCBinary.accept(JCTree.java:1785) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.visitReturn(Attr.java:1724) at com.sun.tools.javac.tree.JCTree$JCReturn.accept(JCTree.java:1384) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:671) at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:687) at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1152) at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82) at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:909) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:671) at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:1040) at org.netbeans.lib.nbjavac.services.NBAttr.visitMethodDef(NBAttr.java:76) at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:778) at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:602) at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:671) at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4481) at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4383) at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4334) at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4316) at com.sun.tools.javac.api.JavacTrees.getElement(JavacTrees.java:346) at com.sun.tools.javac.api.JavacTrees.getElement(JavacTrees.java:124) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitVariable(ElementScanningTask.java:202) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitVariable(ElementScanningTask.java:159) at com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:864) at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:68) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:213) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:159) at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:81) at com.sun.source.util.TreeScanner.scan(TreeScanner.java:91) at com.sun.source.util.TreeScanner.visitBlock(TreeScanner.java:162) at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:918) at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:68) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:213) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:159) at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:81) at com.sun.source.util.TreeScanner.scan(TreeScanner.java:91) at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:99) at com.sun.source.util.TreeScanner.visitClass(TreeScanner.java:133) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitClass(ElementScanningTask.java:187) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitClass(ElementScanningTask.java:159) at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:719) at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:68) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:213) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:159) at com.sun.source.util.TreeScanner.scan(TreeScanner.java:91) at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:99) at com.sun.source.util.TreeScanner.visitCompilationUnit(TreeScanner.java:120) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitCompilationUnit(ElementScanningTask.java:177) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.visitCompilationUnit(ElementScanningTask.java:159) at com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:551) at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:68) at org.netbeans.modules.java.navigation.ElementScanningTask$PositionVisitor.scan(ElementScanningTask.java:213) at org.netbeans.modules.java.navigation.ElementScanningTask.runImpl(ElementScanningTask.java:136) at org.netbeans.modules.java.navigation.ElementScanningTask.run(ElementScanningTask.java:104) at org.netbeans.modules.java.navigation.ElementScanningTask.run(ElementScanningTask.java:85) at org.netbeans.modules.java.source.JavaSourceAccessor$CancelableTaskWrapper.run(JavaSourceAccessor.java:298) at org.netbeans.modules.parsing.impl.TaskProcessor.callParserResultTask(TaskProcessor.java:568) at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:744) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1423) at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)