docs: private void displayValue() {
  
          if (m_resultList == null) {
              if (!m_loadingCategoryTree) {
                  m_loadingCategoryTree = true;
                  // generate a list of all configured categories.
                  final String category = m_category;
                  final String refPath = m_refPath;
                  final boolean showWithRepository = m_showWithRepository;
                  CmsRpcAction<List<CmsCategoryTreeEntry>> action = new CmsRpcAction<List<CmsCategoryTreeEntry>>() {
  
                      /**
                       * @see org.opencms.gwt.client.rpc.CmsRpcAction#onResponse(java.lang.Object)
                       */
                      @Override
                      public void execute() {
  
                          CmsCoreProvider.getService().getCategories(category, true, refPath, showWithRepository, this);
  
                      }
  
                      /**
                       * @see org.opencms.gwt.client.rpc.CmsRpcAction#onResponse(java.lang.Object)
                       */
                      @Override
                      protected void onResponse(List<CmsCategoryTreeEntry> result) {
  
                          // copy the result to the global variable.
                          m_resultList = result;
                          m_loadingCategoryTree = false;
                          // start to generate the tree view.
                          m_categoryField.buildCategoryTree(m_resultList, m_selected);
                          setHeight();
                      }
  
                  };
                  action.execute();
              }
          } else {
              m_categoryField.buildCategoryTree(m_resultList, m_selected);
              setHeight();
          }
      }