  test(data === sb.init(), 'sb returns same data');

      data.x = 10;
      test(data.x === 10, 'x (value) set on data');

      data.y = () => data.x + 5;
      test(data.y === 15, 'y (computed) set on data');

      const rp = document.createElement('red-p').shadowRoot?.lastElementChild
      test(rp instanceof HTMLParagraphElement, 'el red-p has p shadowRoot');
      test(rp.style.color === 'red', 'red-p has style.color red');

      delete data.x;
      delete data.y;
    </script>

    <p id="1" sb-m