java.lang.AssertionError
        at com.sun.tools.javac.code.Types$9.visitType(Types.java:938)
        at com.sun.tools.javac.code.Types$9.visitType(Types.java:1101)
        at com.sun.tools.javac.code.Type.accept(Type.java:96)
        at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:3561)
        at com.sun.tools.javac.code.Types.isCastable(Types.java:912)
        at com.sun.tools.javac.code.Types.isCastable(Types.java:894)
        at org.netbeans.api.java.source.TypeUtilities.isCastable(TypeUtilities.java:75)
        at org.netbeans.modules.java.hints.errors.AddCast.computeType(AddCast.java:158)
        at org.netbeans.modules.java.hints.errors.AddCast.run(AddCast.java:191)
        at org.netbeans.modules.java.hints.infrastructure.CreatorBasedLazyFixList.compute(CreatorBasedLazyFixList.java:144)
        at org.netbeans.modules.java.hints.infrastructure.LazyHintComputation.run(LazyHintComputation.java:109)
        at org.netbeans.modules.java.hints.infrastructure.LazyHintComputation.run(LazyHintComputation.java:55)
        at org.netbeans.modules.java.source.JavaSourceAccessor$CancelableTaskWrapper.run(JavaSourceAccessor.java:288)
        at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:681)
        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$Worker.runTask(ThreadPoolExecutor.java:885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
        at java.lang.Thread.run(Thread.java:637)