[vbezhenar]

If you want null-checking, you can use Nullable annotations. While they're not as good as proper type system, they mostly do the job.

[wtetzner]

But you have to remember to use them in all the right places. Yes, they help, but it's not just about how good they are, it's about people actually using them too. If you're working on a team, you need to worry about whether or not everyone else is correctly using the annotations.