Extend Graphviz to handle compound graphs
This issues is migrated from the wishlist HTML page at https://graphviz.org/doc/todo.html.
Git blame shows this is from 2014:
620a8b3427 (Emden R. Gansner 2014-01-30 15:21:11 -0500 53) Extend Graphviz to handle compound graphs.
Is a compound graph something with many graphs? I'm just guessing