code: function (x, y, width, height, r, strokeWidth) {
  
  		r = isObject(x) ? x.r : r;
  
  		var wrapper = this.createElement('rect').attr({
  				rx: r,
  				ry: r,
  				fill: NONE
  			});
  		return wrapper.attr(
  				isObject(x) ?
  					x :
  					// do not crispify when an object is passed in (as in column charts)
  					wrapper.crisp(strokeWidth, x, y, mathMax(width, 0), mathMax(height, 0))
  			);
  	}
docs: Draw and return a rectangle
  @param {Number} x Left position
  @param {Number} y Top position
  @param {Number} width
  @param {Number} height
  @param {Number} r Border corner radius
  @param {Number} strokeWidth A stroke width can be supplied to allow crisp drawing