code: function() {
              this._.scrollPos = Garnish.$scrollContainer[this.scrollProperty]();
              Garnish.$scrollContainer[this.scrollProperty](this._.scrollPos + this.scrollDist);
  
              this['mouse' + this.scrollAxis] -= this._.scrollPos - Garnish.$scrollContainer[this.scrollProperty]();
              this['realMouse' + this.scrollAxis] = this['mouse' + this.scrollAxis];
  
              this.drag();
  
              this.scrollFrame = Garnish.requestAnimationFrame(this.scrollProxy);
          }
docs: Scroll Window