Ractor -s usability

Hello everyone!

I'm not sure if it's the right place, but it's the best one I found so far)

I'm trying to use Ractors to make an independent vertices that exchange data between each other. Two things I found close to be impossible to implement:
- Ractor::ClosedError can be raised from the Rector.select, but exception doesn't point to what factor is caused it.
- previous point can be partially solved by filtering terminated ractors, as they 100% have closed port. But Ractor doesn't expose its state and doesn't allow to check if either of ports are closed.