@Override
  public Object read(final Element element) {
    final StringDescriptor descriptor = LwXmlReader.getStringDescriptor(element,
                                                                        UIFormXmlConstants.ATTRIBUTE_VALUE,
                                                                        UIFormXmlConstants.ATTRIBUTE_RESOURCE_BUNDLE,
                                                                        UIFormXmlConstants.ATTRIBUTE_KEY);
    if (descriptor == null) {
      throw new IllegalArgumentException("String descriptor value required");
    }
    return descriptor;
  }
@Override
  public Object read(final Element element)