Apparently, IntelliJ platform uses EDT like in Swing. There was a reactive library for Swing, called `RxJava`, but nowadays it looks obsolete and not compatible with RxJava 2+. For example, it's `SwingScheduler` is not compatible with modern `RxJava`.
What to do? What `Rx` library for Swing can be used nowadays? How to use reactive programming in IntelliJ Platform plugin development?