Method url

src/preconnect.js:118–122

* Preconnects to a URL. Always also does a dns-prefetch because * browser support for that is better. * * It is safe to call this method during prerender with any value, * because no action will be performed until the doc is visible. * * It is safe to call this method with non-HTTP

(ampdoc, url, opt_alsoConnecting)

   *    will be used very soon.
   */
  url(ampdoc, url, opt_alsoConnecting) {
    ampdoc.whenFirstVisible().then(() => {
      this.url_(ampdoc, url, opt_alsoConnecting);
    });
  }

  /**
   * Preconnects to a URL. Always also does a dns-prefetch because