code: function (max) {
        if (typeof max !== 'number') return this._max;
        if (max < 1) throw new TypeError('max should be a positive number');
        var shrink = (this._max || 0) > max;
        this._max = max;
        if (shrink) this._trim();
      }
docs: Getter|Setter function of "max" option
  @param {Number} if setter