# Generates a UML class diagram from a `Model`
	fun generate_class_uml: Writable do
		var tpl = new Template
		tpl.add "digraph G \{\n"
		tpl.add """	fontname = "Bitstream Vera Sans"
				fontsize = 8
				node [
					fontname = "Bitstream Vera Sans"
					fontsize = 8
					shape = "record"
				]

				edge [
					fontname = "Bitstream Vera Sans"
					fontsize = 8
				]\n"""
		for mclass in model.collect_mclasses(filter) do
			tpl.add mclass.tpl_class(self)
			tpl.add "\n"
		end
		tpl.add "\}"
		return tpl
	end