docs: public void saveProperties(Command afterSaveCommand) {
  
          Map<String, String> properties = new HashMap<String, String>();
          for (Widget property : m_propertiesPanel) {
              CmsPropertyForm form = ((CmsPropertyForm)property);
              if (form.isChanged()) {
                  properties.put(form.getId(), form.getValue());
              }
          }
          m_handler.saveProperties(properties, afterSaveCommand);
      }