# Collect all classes redefined or refined in `self`
	fun collect_redef_mclasses(filter: nullable ModelFilter): Set[MClass] do
		var res = new HashSet[MClass]
		for mgroup in mgroups do
			for mmodule in collect_all_mmodules(filter) do
				res.add_all mmodule.collect_redef_mclasses(filter)
			end
		end
		return res
	end