docs: private void setKnobPosition(int value) {
  
          int top = (int)(SCROLL_KNOB_OFFSET + (m_positionValueRatio * value));
          int maxPosition = getElement().getOffsetHeight() - m_knobHeight - SCROLL_KNOB_OFFSET;
          top = top < SCROLL_KNOB_OFFSET ? SCROLL_KNOB_OFFSET : (top > maxPosition ? maxPosition : top);
          m_knob.getStyle().setTop(top, Unit.PX);
      }