code: public void updateContentTree() {
  
          m_scrollList.clearList();
          m_childrens.clear();
          m_categories.clear();
          if ((m_resultList != null) && !m_resultList.isEmpty()) {
              // add the first level and children
              for (CmsCategoryTreeEntry category : m_resultList) {
                  // set the category tree item and add to list
                  CmsTreeItem treeItem = buildTreeItem(category, m_selectedCategories);
                  m_childrens.put(treeItem.getId(), new ArrayList<>(category.getChildren().size()));
                  addChildren(treeItem, category.getChildren(), m_selectedCategories);
                  if (!category.getPath().isEmpty() || (treeItem.getChildCount() > 0)) {
                      m_scrollList.add(treeItem);
                  }
                  treeItem.setOpen(!m_showCollapsed);
              }
          } else {
              showIsEmptyLabel();
          }
          scheduleResize();
      }
docs: Updates the content of the categories tree.<p>