docs: void setUpOUComboBox(ComboBox combo) {
  
          combo.removeAllItems();
          try {
              if (m_site != null) {
                  String siteOu = getSiteOU();
                  combo.addItem(siteOu);
                  combo.select(siteOu);
                  combo.setEnabled(false);
              } else {
                  combo.addItem("/");
  
                  m_clonedCms.getRequestContext().setSiteRoot("");
                  List<CmsOrganizationalUnit> ous = OpenCms.getOrgUnitManager().getOrganizationalUnits(
                      m_clonedCms,
                      "/",
                      true);
  
                  for (CmsOrganizationalUnit ou : ous) {
  
                      if (ouIsOK(ou)) {
                          combo.addItem(ou.getName());
                      }
  
                  }
                  combo.select("/");
              }
  
          } catch (CmsException e) {
              LOG.error("Error on reading OUs", e);
          }
          combo.setNullSelectionAllowed(false);
          combo.setTextInputAllowed(true);
          combo.setFilteringMode(FilteringMode.CONTAINS);
          combo.setNewItemsAllowed(false);
  
      }