java.lang.NullPointerException
   at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:3643)
   at com.sun.tools.javac.code.Types$Subst.subst(Types.java:2182)
   at com.sun.tools.javac.code.Types.subst(Types.java:2156)
   at com.sun.tools.javac.comp.Infer.instantiateMethod(Infer.java:400)
   at com.sun.tools.javac.comp.Resolve.rawInstantiate(Resolve.java:393)
   at com.sun.tools.javac.comp.Resolve.instantiate(Resolve.java:428)
   at com.sun.tools.javac.comp.Resolve.signatureMoreSpecific(Resolve.java:824)
   at com.sun.tools.javac.comp.Resolve.mostSpecific(Resolve.java:733)
   at com.sun.tools.javac.comp.Resolve.selectBest(Resolve.java:707)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:927)
   at com.sun.tools.javac.comp.Resolve.findMethod(Resolve.java:891)
   at com.sun.tools.javac.comp.Resolve.resolveQualifiedMethod(Resolve.java:1417)
   at com.sun.tools.javac.comp.Attr.selectSym(Attr.java:2427)
   at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:2320)
   at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:1689)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:454)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:427)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:473)
   at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1480)
   at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1329)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:454)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:427)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:473)
   at com.sun.tools.javac.comp.Attr.visitVarDef(Attr.java:871)
   at com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:733)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:454)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:427)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:504)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:520)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:902)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:789)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:454)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:427)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:504)
   at com.sun.tools.javac.comp.Attr.visitMethodDef(Attr.java:817)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:676)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:454)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:427)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:504)
   at com.sun.tools.javac.comp.Attr.attribClassBody(Attr.java:3235)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:3161)
   at com.sun.tools.javac.comp.Attr.attribClass(Attr.java:3092)
   at com.sun.tools.javac.main.JavaCompiler.attribute(JavaCompiler.java:1239)
   at com.sun.tools.javac.api.JavacTaskImpl$2.process(JavacTaskImpl.java:480)
   at com.sun.tools.javac.api.JavacTaskImpl$Filter.run(JavacTaskImpl.java:631)
   at com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:483)
   at org.netbeans.modules.java.source.indexing.MultiPassCompileWorker.compile(MultiPassCompileWorker.java:244)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1.run(JavaCustomIndexer.java:198)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer$1.run(JavaCustomIndexer.java:160)
   at org.netbeans.modules.java.source.usages.ClassIndexManager.prepareWriteLock(ClassIndexManager.java:120)
   at org.netbeans.modules.java.source.indexing.JavaCustomIndexer.index(JavaCustomIndexer.java:160)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor$2.run(Indexable.java:153)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater.runIndexer(RepositoryUpdater.java:256)
   at org.netbeans.modules.parsing.spi.indexing.Indexable$MyAccessor.index(Indexable.java:151)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doIndex(RepositoryUpdater.java:1823)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.access$1400(RepositoryUpdater.java:1563)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$2.run(RepositoryUpdater.java:1743)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work$2.run(RepositoryUpdater.java:1741)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:459)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:1741)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:3427)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:3328)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:3071)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.doTheWork(RepositoryUpdater.java:2158)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task._run(RepositoryUpdater.java:3822)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Task.run(RepositoryUpdater.java:3761)
   at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:610)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
   at java.util.concurrent.FutureTask.run(FutureTask.java:138)
   at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
   at java.lang.Thread.run(Thread.java:662)