overriders contain more definitions than introductions

Property definitions

nitc :: mendel_metrics $ MClass :: is_overrider
	# overriders contain more definitions than introductions
	private fun is_overrider(filter: ModelFilter): Bool do
		var rdfs = collect_redef_mproperties(filter).length
		var news = collect_intro_mproperties(filter).length
		var locs = collect_local_mproperties(filter).length
		if rdfs >= news and locs > 0 then return true
		return false
	end
src/metrics/mendel_metrics.nit:292,2--299,4