text: function createStylesheetLink(url) {
      var link = document.createElement('link');
      link.rel = 'stylesheet';
      link.href = url;
      return link;
  }
  // TODO: export this function?
  // check if the css url has been injected or added manually
  function getCss(url) {
      return document.querySelector("link[href*=\"" + url + "\"]");
  }
  // lazy load the CSS needed for the ArcGIS API
  export function loadCss(url) {
      var link = getCss(url);
      if (!link) {
          // create & load the css library
          link = createStylesheetLink(url);
          document.head.appendChild(link);
      }
      return link;
  }
  