Package in ActivityDiagram3

Question

Hi!

I would like to add the notion of a process to SDL diagrams. However this requires ActivityDiagram3 to extends AbstractEntityDiagram this causes many problems. Is there an easier way to add a group to ActivityDiagram 3?

Concretely, I would like to be able to have something like

package MyProcess <<Rect>> {

  :Ready;

}

 

or 

 

process MyProcess {

  :Ready;

}

 

I created a ProcessCommand based on PackageCommand but all I managed to do is crash Graphviz.