The example you show is just a bad workaround though: Your real problem there is that you have code that deals with input that can be null, but whose job is not

The example you show is just a bad workaround though: Your real problem there is that you have code that deals with input that can be null, but whose job is not just to get rid of the nullability. Keeping around fields that could be null and looking for ways to do it safely is like forcing everyone to wear radiations suits because you refuse to have laws about where you can keep nuclear materials. This is why in modern Java, or in Scala, we have Option types (and in old school java, Nullable annotations), which makes trickery like that unnecessary.