When overriding an upstream method, copying the original method code
should always be a last resort, as the two code bases tend to get
out of sync and it often becomes hard to spot the modifications done
by the override. Both those issues can be avoided when figuring out
a way to split out the modifications and call the unmodified upstream
method - we are in luck with our checkWorkspaces() override, as we
can trick the upstream method into not removing workspaces we want
to keep instead of copying the method altogether.
https://gitlab.gnome.org/GNOME/gnome-shell-extensions/issues/33
3b6cd04a59