code: function () {
        this._objects.push.apply(this._objects, arguments);
        for (var i = arguments.length; i--; ) {
          this._initObject(arguments[i]);
        }
        this.renderOnAddition && this.renderAll();
        return this;
      }
docs: Adds objects to canvas, then renders canvas;
  Objects should be instances of (or inherit from) fabric.Object
  @method add
  @return {fabric.Canvas} thisArg
  @chainable