java.lang.NullPointerException
   at com.sun.tools.javac.code.Types.makeFunctionalInterfaceClass(Types.java:638)
   at com.sun.tools.javac.comp.Attr.setFunctionalInfo(Attr.java:3094)
   at com.sun.tools.javac.comp.Attr.visitLambda(Attr.java:2454)
   at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1630)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.DeferredAttr$2.complete(DeferredAttr.java:284)
   at com.sun.tools.javac.comp.DeferredAttr$DeferredType.check(DeferredAttr.java:245)
   at com.sun.tools.javac.comp.DeferredAttr$DeferredType.check(DeferredAttr.java:232)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.recover(DeferredAttr.java:891)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.typeOf(DeferredAttr.java:861)
   at com.sun.tools.javac.comp.DeferredAttr$DeferredTypeMap.apply(DeferredAttr.java:827)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.apply(DeferredAttr.java:880)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.map(DeferredAttr.java:909)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.map(DeferredAttr.java:907)
   at com.sun.tools.javac.comp.DeferredAttr$RecoveryDeferredTypeMap.apply(DeferredAttr.java:871)
   at com.sun.tools.javac.code.Type$ForAll.map(Type.java:1419)
   at com.sun.tools.javac.comp.Attr.checkMethodIdInternal(Attr.java:3734)
   at com.sun.tools.javac.comp.Attr.checkMethodId(Attr.java:3710)
   at com.sun.tools.javac.comp.Attr.checkId(Attr.java:3698)
   at com.sun.tools.javac.comp.Attr.visitIdent(Attr.java:3446)
   at com.sun.tools.javac.tree.JCTree$JCIdent.accept(JCTree.java:2017)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1881)
   at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1471)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:662)
   at com.sun.tools.javac.comp.Attr.visitExec(Attr.java:1646)
   at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1302)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:682)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:698)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1167)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:915)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:682)
   at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:1055)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitMethodDef(NBAttr.java:76)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:784)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:613)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:682)
   at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:4572)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4474)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:4402)
   at com.sun.tools.javac.comp.Attr.attrib(Attr.java:4377)
   at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1311)
   at com.sun.tools.javac.api.JavacTaskImpl$1.process(JavacTaskImpl.java:473)
   at com.sun.tools.javac.api.JavacTaskImpl$Filter.run(JavacTaskImpl.java:623)
   at com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:476)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:272)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:250)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:161)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:283)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:159)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:2650)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$1600(RepositoryUpdater.java:2091)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2539)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$1.run(RepositoryUpdater.java:2537)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:544)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:2537)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:5367)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:5076)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:4717)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:3267)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:5810)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.access$5300(RepositoryUpdater.java:5476)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3$1.run(RepositoryUpdater.java:5735)
   at org.netbeans.modules.parsing.impl.RunWhenScanFinishedSupport.performScan(RunWhenScanFinishedSupport.java:96)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5731)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task$3.call(RepositoryUpdater.java:5727)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:74)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:5727)
   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:1423)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2033)