realized i couldn't get all the way into it so leaving it as a WIP for now and will get to it in the next few days, but i'm pretty sure the idea here will work (allowing duplicate PathStats in a Snapshot if they originate from the same base directory): https://github.com/pantsbuild/pants/pull/6500

if(obj != null)

is not bad itself Maybe you could show to your team members good examples how to eliminate nullability in particular cases

For the code that we don't control there is no other way. We must check the nulls. But I wouldn't agree that we have to make everything nullable in the code we own and control.

Back to Java? Why?

Right, but I meant even Java tries to wrap the null into am object. The null is not an object and into my eyes simply doesn't fit in the OOP

I disagree

Well ok. I was asking for arguments against it, not for it :)

Kotlin gives a power or type system and tools to handle nullability gracefully

And maintain

Just take some class and elliminate nulls where it’s possible to show an example for team mates

That's something we are going to try for sure. That's great point.

Also some idioms help to improve code with nulls in some cases, like early return, default arguments and so on