code: private void initFolderTree(boolean showInvisible) throws CmsException {
  
          CmsObject cms = A_CmsUI.getCmsObject();
          m_treeContainer.removeAllItems();
          try {
              CmsResource siteRoot = cms.readResource("/", FOLDERS);
              addTreeItem(cms, siteRoot, null, false, m_treeContainer);
          } catch (CmsException e) {
              if (showInvisible) {
                  CmsResource siteRoot = cms.readResource("/", CmsResourceFilter.IGNORE_EXPIRATION);
                  addTreeItem(cms, siteRoot, null, true, m_treeContainer);
              } else {
                  throw e;
              }
          }
  
      }
docs: Populates the folder tree.<p>
  
  @param showInvisible to show non visible root folder as disabled
  
  @throws CmsException in case reading the root folder fails