t2.cssRules[0].cssText, redStyleTexts[1]);

  sheet2.deleteRule(0);
  assert_equals(sheet2.cssRules.length, 0);

  const sheet3 = new CSSStyleSheet();
  assert_equals(sheet3.title, null, "The title attribute must return the title or null if title is the empty string");
  assert_equals(sheet3.ownerNode, null);
  assert_equals(sheet3.ownerRule, null);
  assert_equals(sheet3.media.length, 0);
  assert_false(sheet3.disabled);
  assert_equals(sheet3.cssRules.length, 0);

  sheet3.insertRule(redStyleTexts[1]);
  