I’d like to extend fastutil’s Long2ObjectOpenHashMap java class so I can access its protected fields. It works in Scala 2.13.10 but not in Scala 3.3.0 (nor 3.3.3). Added the error as comment in the source.

https://github.com/tewecske/scala3-fastutil/blob/master/backend/src/main/scala/base/Long2ObjectOpenMapScala.scala

Is this a Scala 3 issue or the fastutil class is not compatible with it? Is there a way to solve it?