ed features for stamped templates:
   *
   * - Declarative event listeners (`on-eventname="listener"`)
   * - Map of node id's to stamped node instances (`this.$.id`)
   * - Nested template content caching/removal and re-installation (performance
   *   optimization)
   *
   * @polymerMixin
   * @memberof Polymer
   * @summary Element class mixin that provides basic template parsing and stamping
   */
  Polymer.TemplateStamp = Polymer.dedupingMixin(superClass => {

    /**
     * @polymerMixinClass
     * @