text: var Example = Example || {};
  
  Example.pyramid = function() {
      var Engine = Matter.Engine,
          Render = Matter.Render,
          Runner = Matter.Runner,
          Composites = Matter.Composites,
          MouseConstraint = Matter.MouseConstraint,
          Mouse = Matter.Mouse,
          World = Matter.World,
          Bodies = Matter.Bodies;
  
      // create engine
      var engine = Engine.create(),
          world = engine.world;
  
      // create renderer
      var render = Render.create({
          element: document.body,
          engine: engine,
          options: {
              width: 800,
              height: 600,
              showAngleIndicator: true
          }
      });
  
      Render.run(render);
  
      // create runner
      var runner = Runner.create();
      Runner.run(runner, engine);
  
      // add bodies
      var stack = Composites.pyramid(100, 258, 15, 10, 0, 0, function(x, y) {
          return Bodies.rectangle(x, y, 40, 40);
      });
      
      World.add(world, [
          stack,
          // walls
          Bodies.rectangle(400, 0, 800, 50, { isStatic: true }),
          Bodies.rectangle(800, 300, 50, 600, { isStatic: true }),
          Bodies.rectangle(0, 300, 50, 600, { isStatic: true }),
          Bodies.rectangle(400, 605, 800, 50, { isStatic: true })
      ]);
  
      // add mouse control
      var mouse = Mouse.create(render.canvas),
          mouseConstraint = MouseConstraint.create(engine, {
              mouse: mouse,
              constraint: {
                  stiffness: 0.2,
                  render: {
                      visible: false
                  }
              }
          });
  
      World.add(world, mouseConstraint);
  
      // keep the mouse in sync with rendering
      render.mouse = mouse;
  
      // fit the render viewport to the scene
      Render.lookAt(render, {
          min: { x: 0, y: 0 },
          max: { x: 800, y: 600 }
      });
  
      // context for MatterTools.Demo
      return {
          engine: engine,
          runner: runner,
          render: render,
          canvas: render.canvas,
          stop: function() {
              Matter.Render.stop(render);
              Matter.Runner.stop(runner);
          }
      };
  };