code: public void saveContent(
          JavaScriptObject newValues,
          final I_CmsStringCallback onSuccess,
          final I_CmsErrorCallback onFailure) {
  
          m_apiRoot.getRpcHelper().executeRpc(
              CmsXmlContentUgcApi.SERVICE.saveContent(
                  m_content.getSessionId(),
                  CmsJsUtils.convertJsObjectToMap(newValues),
                  new AsyncCallback<Map<String, String>>() {
  
                      @SuppressWarnings("synthetic-access")
                      public void onFailure(Throwable caught) {
  
                          CmsUgcException formException = (CmsUgcException)caught;
                          m_apiRoot.handleError(formException, onFailure);
                      }
  
                      public void onSuccess(Map<String, String> result) {
  
                          if ((result == null) || result.isEmpty()) {
                              onSuccess.call("");
                          } else {
                              JavaScriptObject validationErrorsJso = CmsJsUtils.convertMapToJsObject(result);
                              onFailure.call(CmsUgcConstants.ErrorCode.errValidation.toString(), "", validationErrorsJso);
                          }
                      }
                  }));
  
      }
docs: Asks the server to save the values set via setNewValue in the XML content.<p>
  
  @param newValues the new values to set
  @param onSuccess the callback to be called in case of success
  @param onFailure the callback to be called in case of failure