Why the BPMN group object does not exist in the gojs library

BPMN Group template exists between BPMN objects.
I need help creating such a BPMN template and I would be very grateful if you could support.

As in the image below

What problem did you encounter?


Problem: Why is this object missing in BPMN project?


I’m not that familiar with BPMN, but what is that? We don’t claim to have a complete implementation of the BPMN 2.0 graphics in our BPMN sample, but I don’t see it in https://www.omg.org/spec/BPMN/2.0.2/PDF.

If the syntax and semantics are simple enough, it could be simple for you to implement.