 {
        // This code is used to generate reference data for the tests.
        let text = `data-expected-width="${el.offsetWidth}" data-expected-height="${el.offsetHeight}" data-offset-y="${el.offsetTop}" data-offset-x="${el.offsetLeft}"`;
        el.parentElement.innerText = text;
        return;
      }
      assert_equals(el.offsetWidth + "", el.getAttribute("data-expected-width"), "incorrect offsetWidth");
      assert_equals(el.offsetHeight + "", el.getAttribute("data-expected-height"), "incorrect o