(function() { var World = Matter.World, Bodies = Matter.Bodies, Composites = Matter.Composites; Example.stack = function(demo) { var engine = demo.engine, world = engine.world; var stack = Composites.stack(100, 380, 10, 5, 0, 0, function(x, y) { return Bodies.rectangle(x, y, 40, 40); }); World.add(world, stack); }; })();