legacyElementFactory = function(config, children) {
    // This factory should not be called when JSX is used. Use JSX instead.
    if ("production" !== process.env.NODE_ENV) {
      warnForLegacyFactoryCall();
    }
    return factory.apply(this, arguments);
  }
@param {string} markup to use
@param {DOMElement} element root React element
@returns {boolean} whether or not the markup is the same