docs: public void updatePadding() {
  
          if (!isAttached()) {
              // only update panel when attached to DOM
              return;
          }
  
          int panelWidth = getOffsetWidth();
          // avoid negative widths
          if (panelWidth > (2 * m_paddingX)) {
              getWidget().setWidth((panelWidth - (2 * m_paddingX)) + "px");
          }
          getElement().getStyle().setPaddingLeft(m_paddingX, Unit.PX);
          getElement().getStyle().setPaddingRight(m_paddingX, Unit.PX);
      }