code: public void updateLayout() {
  
          // TODO: we should not do this kind of things...
          if (!isAttached()) {
              return;
          }
          int floatBoxWidth = getFloatBoxWidth();
          m_primary.getElement().getStyle().setMarginLeft(floatBoxWidth, Unit.PX);
          updateVerticalMargin();
      }
docs: Sets the left margin of the main panel to the width of the float panel.<p>