I want to add Footer in myDiagram canvas

I need to add footer in canvas of myDiagram. How will I do the same?

Would you want it to be part of your model or not?
If yes, just add another category to your Diagram.nodeTemplateMap.

If not, just create the Part and call Diagram.add.
If it is a Part and not a Node, remember to assign its Part.location because the TreeLayout won’t do it.