code: protected void closePopup() {
  
          List<String> result;
  
          if (m_previewHandlerRegistration != null) {
              m_previewHandlerRegistration.removeHandler();
              m_previewHandlerRegistration = null;
          }
          if (m_isSingleValue) {
              result = m_cmsCategoryTree.getSelected();
          } else {
              result = m_cmsCategoryTree.getAllSelectedSitePath();
          }
          m_selected.clear();
          m_selected.addAll(result);
          displayValue();
          m_cmsPopup.hide();
          fireChangeEvent();
  
      }
docs: Is called to close the popup and show the new values.<p>