java.lang.NullPointerException
   at com.sun.tools.javac.code.Types$DescriptorFilter.accepts(Types.java:734)
   at com.sun.tools.javac.code.Types$DescriptorFilter.accepts(Types.java:721)
   at com.sun.tools.javac.code.Scope$ScopeImpl$1$1.skipToNextMatchingEntry(Scope.java:605)
   at com.sun.tools.javac.code.Scope$ScopeImpl$1$1.update(Scope.java:594)
   at com.sun.tools.javac.code.Scope$ScopeImpl$1$1.<init>(Scope.java:573)
   at com.sun.tools.javac.code.Scope$ScopeImpl$1.iterator(Scope.java:569)
   at com.sun.tools.javac.code.Scope$CompoundScope.lambda$null$8(Scope.java:1006)
   at com.sun.tools.javac.util.Iterators$CompoundIterator.hasNext(Iterators.java:57)
   at com.sun.tools.javac.code.Types$DescriptorCache.findDescriptorInternal(Types.java:420)
   at com.sun.tools.javac.code.Types$DescriptorCache.get(Types.java:399)
   at com.sun.tools.javac.code.Types.findDescriptorSymbol(Types.java:568)
   at com.sun.tools.javac.code.Types.isFunctionalInterface(Types.java:584)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck$MostSpecificCheckContext.unrelatedFunctionalInterfaces(Resolve.java:1131)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck$MostSpecificCheckContext.compatible(Resolve.java:1111)
   at com.sun.tools.javac.comp.Check.checkType(Check.java:571)
   at com.sun.tools.javac.comp.Attr$ResultInfo.check(Attr.java:498)
   at com.sun.tools.javac.comp.Resolve$MostSpecificCheck.argumentsAcceptable(Resolve.java:1079)
   at com.sun.tools.javac.comp.Resolve.rawInstantiate(Resolve.java:588)
   at com.sun.tools.javac.comp.Resolve.instantiate(Resolve.java:634)
   at com.sun.tools.javac.comp.Resolve.signatureMoreSpecific(Resolve.java:1587)
   at com.sun.tools.javac.comp.Resolve.mostSpecific(Resolve.java:1516)
   at com.sun.tools.javac.comp.Resolve.selectBest(Resolve.java:1494)
   at com.sun.tools.javac.comp.Resolve.findMethodInScope(Resolve.java:1654)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1723)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:1697)
   at com.sun.tools.javac.comp.Resolve$9.doLookup(Resolve.java:2404)
   at com.sun.tools.javac.comp.Resolve$BasicLookupHelper.lookup(Resolve.java:3014)
   at com.sun.tools.javac.comp.Resolve.lookupMethod(Resolve.java:3264)
   at com.sun.tools.javac.comp.Resolve.resolveQualifiedMethod(Resolve.java:2401)
   at com.sun.tools.javac.comp.Resolve.resolveQualifiedMethod(Resolve.java:2395)
   at com.sun.tools.javac.comp.Attr.selectSym(Attr.java:3736)
   at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:3614)
   at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2075)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1935)
   at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1604)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:674)
   at com.sun.tools.javac.comp.Attr.visitVarDef(Attr.java:1163)
   at com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:926)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:705)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:729)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1211)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:990)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:705)
   at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:1097)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitMethodDef(NBAttr.java:76)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:842)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:705)
   at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4686)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4585)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4513)
   at com.sun.tools.javac.comp.Attr.attrib(Attr.java:4488)
   at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1282)
   at com.sun.tools.javac.api.JavacTaskImpl$4.process(JavacTaskImpl.java:475)
   at com.sun.tools.javac.api.JavacTaskImpl$Filter.run(JavacTaskImpl.java:607)
   at com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:478)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:268)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:251)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:296)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2753)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$500(RepositoryUpdater.java:2157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2639)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:565)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2637)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3290)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$3.call(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$4.run(RepositoryUpdater.java:2130)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2126)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runInContext(RepositoryUpdater.java:2107)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.access$1200(RepositoryUpdater.java:157)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.scanFiles(RepositoryUpdater.java:3256)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$FileListWork.getDone(RepositoryUpdater.java:3775)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3410)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:6173)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$4300(RepositoryUpdater.java:5824)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2$1.run(RepositoryUpdater.java:6089)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:304)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:106)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2.call(RepositoryUpdater.java:6085)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$2.call(RepositoryUpdater.java:6081)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:6081)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)