var styleElement = document.createElement("style");
styleElement.textContent = '#useless {width: 300px}';
// Insert before style sheet s2 in order to trigger style resolver reconstruction.
-document.getElementById('s2').insertBefore(styleElement);
+document.getElementById('s2').insertBefore(styleElement, null);
shouldBe("getComputedStyle(target).width", '"200px"');