code: function renderToStaticMarkup(element) {
    !React.isValidElement(element) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'renderToStaticMarkup(): You must pass a valid ReactElement.') : _prodInvariant('47') : void 0;
    return renderToStringImpl(element, true);
  }
docs: Similar to renderToString, except this doesn't create extra DOM attributes
  such as data-react-id that React uses internally.
  See https://facebook.github.io/react/docs/top-level-api.html#reactdomserver.rendertostaticmarkup