code: function () {
          this.requires("2D");
          var area = this._mbr || this;
  
          var poly = new Crafty.polygon([0, 0], [area._w, 0], [area._w, area._h], [0, area._h]);
          this.map = poly;
          this.attach(this.map);
          this.map.shift(area._x, area._y);
      }
docs: @
  #.init
  @comp Collision
  Create a rectangle polygon based on the x, y, w, h dimensions.
  
  You must ensure that the x, y, w, h properties are set before the init function is called. If you have a Car component that sets these properties you should create your entity like this
  ~~~
  Crafty.e('2D, DOM, Car, Collision');
  ~~~
  And not like
  ~~~
  Crafty.e('2D, DOM, Collision, Car');
  ~~~