code: function addShape(shape, batchInsert) {
           if (shape instanceof me.Rect) {
             this.shapes.push(shape.toPolygon());
           } else {
             // else polygon or circle
             this.shapes.push(shape);
           }
  
           if (batchInsert !== true) {
             // update the body bounds to take in account the added shape
             this.updateBounds();
           } // return the length of the shape list
  
  
           return this.shapes.length;
         }
docs: add a collision shape to this body <br>
  (note: me.Rect objects will be converted to me.Polygon before being added)
  @name addShape
  @memberOf me.Body
  @public
  @function
  @param {me.Rect|me.Polygon|me.Line|me.Ellipse} shape a shape object
  @param {Boolean} batchInsert if true the body bounds won't be updated after adding a shape
  @return {Number} the shape array length