nst shadowDiv = attachShadowDiv(span);
  const targetSpan = document.createElement("span");
  targetSpan.classList.add("target");
  shadowDiv.appendChild(targetSpan);
  const sheet = new CSSStyleSheet();
  span.shadowRoot.adoptedStyleSheets = [sheet];
  assert_equals(getComputedStyle(shadowDiv).color, "rgb(0, 0, 0)");
  // Replace and assert that the imported rule is NOT applied, but regular rule does apply.
  const sheet_promise = sheet.replace(import_text + ".target { color: blue; }");
  return sheet_prom