       var selector = document.createElement('iron-selector');
          selector.selected = '0';
          document.body.appendChild(selector);

          // Create and append a new item which should become selected.
          var child = document.createElement('div');
          child.textContent = 'Item 0';
          Polymer.dom(selector).appendChild(child);

          selector.addEventListener('iron-items-changed', function onIronItemsChanged() {
            selector.removeEventListener('iron-items-chang