Today: • Wanted to try handling _sharedBox_create and stuff around that (looks like it's about capturing vars in lambdas) but bumped into incomplete support for lambdas (we support only lambdas with a single return but in Kotlin many expressions in a lambda are possible). • Spent the most time of the day trying to create a lowering that creates functions for complex lambdas. Took inspiration in CallableReferenceLowering and in InteropCallableReferenceLowering, tried hard, but managed nothing: there are many problems and I still don't know IR well enough. • Tried to continue a temporary solution for lambdas support in the IR2PyAST that we now have, it's ugly but it works. I have +43 box tests passing without regressions now. However, there can be some more improvements so I don't open a PR for now. The next week I will be on vacation so probably I won't do anything. Next time: • Finish with that ugly support for multiline lambdas. • Probably start with _sharedBox_create.

Thanks for the awesome work and enjoy your vacation :) do you mind if I rebase your PR about secondary constructors and if it works good, merge it?

Thank you! Oops, I've seen your message too late: I've rebased it already. Will request review when CI passes.