gistfile1.js

      loadLinks: function(urls) {
        // HTMLImports polyfill can load links out of documents,
        // so make a document and put our links in it
        var doc = document.createDocumentFragment();
        urls.forEach(function(url) {
          var link = doc.appendChild(document.createElement('link'));
          link.rel = "import";
          link.href = url;
        });
        // ask the polyfill to load the links, do custom parsing
        // stuff when they are ready
        HTMLImports.importer.load(doc, function() {
          doc.querySelectorAll('link').array().forEach(
            function(link) {
              HTMLImports.parser.parse(link.content);
              CustomElements.parser.parse(link.content);
            }
          );
        });
      },