# Collect all classes imported from `self` parents
	fun collect_imported_mclasses(mainmodule: MModule, filter: nullable ModelFilter): Set[MClass] do
		var res = new HashSet[MClass]
		for parent in collect_parents(mainmodule, filter) do
			res.add_all parent.collect_intro_mclasses(filter)
			res.add_all parent.collect_redef_mclasses(filter)
			res.add_all parent.collect_imported_mclasses(mainmodule, filter)
		end
		return res
	end