The following lines do not compile in Netbeans:

 java.io.File f = null;
 Collections.singleton(Optional.ofNullable(Optional.ofNullable(f).orElseThrow(null).getName()).orElseThrow(null));

The error is:
error: unreported exception X; must be caught or declared to be thrown
        Collections.singleton(Optional.ofNullable(Optional.ofNullable(f).orElseThrow(null).getName()).orElseThrow(null));
  where X,T are type-variables:
    X extends Throwable declared in method <X>orElseThrow(Supplier<? extends X>)
    T extends Object declared in class Optional

__

No problem is reported by the standard compiler (javac 1.8.0_91). Please ignore the fact that the code makes no sense, it is just a minimal demonstration of the compile time problem.

Workaround: add type hint like this:
 Collections.<String>singleton ...