code: public void validate(JavaScriptObject newValues, final I_CmsJavaScriptObjectCallback onSuccess) {
  
          AsyncCallback<Map<String, String>> rpcCallback = new AsyncCallback<Map<String, String>>() {
  
              @SuppressWarnings("synthetic-access")
              public void onFailure(Throwable caught) {
  
                  m_apiRoot.handleError(caught, null);
              }
  
              public void onSuccess(Map<String, String> result) {
  
                  if (result == null) {
                      result = Maps.newHashMap();
                  }
                  onSuccess.call(CmsJsUtils.convertMapToJsObject(result));
              }
          };
          m_apiRoot.getRpcHelper().executeRpc(
              CmsXmlContentUgcApi.SERVICE.validateContent(
                  m_content.getSessionId(),
                  CmsJsUtils.convertJsObjectToMap(newValues),
                  rpcCallback));
  
      }
docs: Validates the new content values.<p>
  
  @param newValues a Javascript object with the value xpaths as keys and the corresponding content values as values.<p>
  
  @param onSuccess the callback to call with the validation results