# Generates a UML package diagram from a `Model`
	fun generate_package_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"""
		tpl.add mainmodule.tpl_module(self)
		tpl.add "\}"
		return tpl
	end