java.lang.NullPointerException
   at com.sun.tools.javac.code.Types$Subst.visitTypeVar(Types.java:2967)
   at com.sun.tools.javac.code.Types$Subst.visitTypeVar(Types.java:2905)
   at com.sun.tools.javac.code.Type$TypeVar.accept(Type.java:1289)
   at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:4579)
   at com.sun.tools.javac.code.Types$Subst.subst(Types.java:2928)
   at com.sun.tools.javac.code.Types$Subst.subst(Types.java:2936)
   at com.sun.tools.javac.code.Types$Subst.subst(Types.java:2937)
   at com.sun.tools.javac.code.Types$Subst.visitClassType(Types.java:2983)
   at com.sun.tools.javac.code.Types$Subst.visitClassType(Types.java:2905)
   at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:778)
   at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:4579)
   at com.sun.tools.javac.code.Types$Subst.subst(Types.java:2928)
   at com.sun.tools.javac.code.Types.subst(Types.java:2902)
   at org.netbeans.api.java.source.TypeUtilities.substitute(TypeUtilities.java:130)
   at org.netbeans.modules.java.completion.JavaCompletionTask.getMatchingArgumentTypes(JavaCompletionTask.java:5193)
   at org.netbeans.modules.java.completion.JavaCompletionTask.getSmartTypesImpl(JavaCompletionTask.java:4794)
   at org.netbeans.modules.java.completion.JavaCompletionTask.getSmartTypes(JavaCompletionTask.java:4531)
   at org.netbeans.modules.java.completion.JavaCompletionTask.addMembers(JavaCompletionTask.java:3142)
   at org.netbeans.modules.java.completion.JavaCompletionTask.insideMemberSelect(JavaCompletionTask.java:1551)
   at org.netbeans.modules.java.completion.JavaCompletionTask.resolve(JavaCompletionTask.java:322)
   at org.netbeans.modules.java.completion.BaseTask.run(BaseTask.java:92)
   at org.netbeans.modules.java.completion.JavaCompletionTask.run(JavaCompletionTask.java:80)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:609)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:153)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:137)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:204)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:201)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
Caused: org.netbeans.modules.parsing.spi.ParseException
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:209)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:104)
   at org.netbeans.modules.editor.java.JavaCompletionProvider$JavaCompletionQuery.query(JavaCompletionProvider.java:234)
   at org.netbeans.spi.editor.completion.support.AsyncCompletionTask.run(AsyncCompletionTask.java:223)
   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)