code: function syncScrollbar() {
              if ($handle) {
                  hPos.cur = pos.start === pos.end ? 0 : (((!dragging.released && dragging.source === 'handle') ? pos.dest : pos.cur) - pos.start) / (pos.end - pos.start) * hPos.end;
                  hPos.cur = within(Math.round(hPos.cur), hPos.start, hPos.end);
                  if (last.hPos !== hPos.cur) {
                      last.hPos = hPos.cur;
                      if (transform) {
                          $handle[0].style[transform] = gpuAcceleration + (o.horizontal ? 'translateX' : 'translateY') + '(' + hPos.cur + 'px)';
                      } else {
                          $handle[0].style[o.horizontal ? 'left' : 'top'] = hPos.cur + 'px';
                      }
                  }
              }
          }
docs: Synchronizes scrollbar with the SLIDEE.
  
  @return {Void}