Can't shutdown background threads [Firebase Admin SDK 4.1.5] #10

Running this on local machine with Java 8
FirebaseOptions options = new FirebaseOptions.Builder() .setCredential(FirebaseCredentials.applicationDefault()) .setDatabaseUrl("https://" + ServiceOptions.getDefaultProjectId() + ".firebaseio.com/") .build();

firebaseDatabase = FirebaseDatabase.getInstance(FirebaseApp.initializeApp(options)); final DatabaseReference entry = firebaseDatabase.getReference("somereference"); entry.setValue("data",(databaseError, databaseReference) -> System.out.println("ok"));
How can i choose to use daemon threads? And if not, why don't you have a shutdown/close option?

I notice that entry.setValue("data") shutdowns threads normally.