def create_default_groups(self):
        for group in self.groups:
            group = group.replace(" ", "_").lower()
            self[group] = NamedRequirements(group)
def draw_paths(c, tree):
	if tree.lchild == None or tree.rchild == None:
		return
	tree.lchild.leaf.draw_path(c, tree.rchild.leaf)
	draw_paths(c, tree.lchild)
	draw_paths(c, tree.rchild)