With a good IDE configured to break on nullability errors, @Nonnull and @Nullable can also be used to replace the C# system in practice (not the same, but close

With a good IDE configured to break on nullability errors, @Nonnull and @Nullable can also be used to replace the C# system in practice (not the same, but close enough). Unfortunately, this requires coordination from different team members and external dependencies rather than standard language features.