attr id="select">
      <x-attr id="attr1"></x-attr>
      <x-attr2 id="attr2"></x-attr2>
    </x-select-attr>
  </template>
  <script type="module">
import '../../polymer-legacy.js';
import { Polymer } from '../../lib/legacy/polymer-fn.js';
Polymer({is: 'x-compose-select-attr'});
</script>
</dom-module>


<dom-module id="x-clonate">
  <template><span>[</span><slot></slot><span>]</span></template>
  <script type="module">
import '../../polymer-legacy.js';
import { Polymer } from '../../lib/legacy/polymer-fn