ySelector('x-sample#inContainer');
          makeElement('x-sample', function () {
            this.shadowRoot.querySelector('h2').textContent = `${this.id}`;
          });
          makeElement('x-container');
          setTimeout(() => {
            let body = stamp(document.body, inBody);
            let container = stamp(
              document.querySelector('x-container').shadowRoot,
              inContainer
            );
            requestAnimationFrame(() => {
              assert.equal(
         