docs: 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);
      }