xpected-height'))
            flexItem.setAttribute('data-expected-height', 100);
        if (!flexItem.hasAttribute('data-expected-width'))
            flexItem.setAttribute('data-expected-width', 100);
    }
    [].forEach.call(document.querySelectorAll(".flexbox > div"), addExpectedSizes);
    [].forEach.call(document.querySelectorAll(".border-box"), addExpectedSizes);
</script>
</body>
</html>
