code: function() {
  
          var el = this.thumb.getEl();
  
          if (el) {
              /**
               * The center of the slider element is stored so we can 
               * place it in the correct position when the background is clicked.
               * @property thumbCenterPoint
               * @type {"x": int, "y": int}
               */
              this.thumbCenterPoint = { 
                      x: parseInt(el.offsetWidth/2, 10), 
                      y: parseInt(el.offsetHeight/2, 10) 
              };
          }
  
      }
docs: When the thumb is available, we cache the centerpoint of the element so
  we can position the element correctly when the background is clicked
  @method setThumbCenterPoint