Alexander Rimer

Just to provide more information I add the concept declaration of this `OutPort` concept and the hierarchy it is in. Maybe there is a problem with inherited references/children?

@slisson do we already place the missing licence files in the mentioned folder or/and with the plugin already?

Maybe the missing functionality could be added the the [copy](http://127.0.0.1:63320/node?ref=r%3A18e93978-2322-49a8-aaab-61c6faf67e2a%28de.q60.mps.shadowmodels.runtime.engine%29%2F2573073122887783247) function?

Addig a `NodeAttribute` could be achvieved however by transforming the input and + adding attribute like this:

I don't get it. Does this change fix the Crossmodel-generation issue 🤔

@HeikoBecker the target branch [maintenance/mps20211](https://github.com/IETS3/iets3.opensource/tree/maintenance/mps20211) is no longer under maintenance. Do you mind updating it to `maintenance/mps20213`?

@HeikoBecker I've updated the build script and ran some panding migrations. Hope this is OK for you.

@wsafonov could you scatch a short scenario where this is needed?

@wsafonov is this ticket still required in any way or can we just close it? To my knowledge instance tree impl. was done on iests3.core.

@markusvoelter in case this PR is still relevant, could you please adress the latest findings/comments of Wladi?