firefox/testing/web-platform/tests/css/css-flexbox/stretch-flex-item-checkbox-input-ref.html

<!DOCTYPE html>
<input type="checkbox" style="display: block; width: 50px; height: 50px; margin: 0;">
<input type="checkbox" style="display: block; width: 50px; height: 50px; margin: 0;">
	`<!DOCTYPE html>`
	`<input type="checkbox" style="display: block; width: 50px; height: 50px; margin: 0;">`
	`<input type="checkbox" style="display: block; width: 50px; height: 50px; margin: 0;">`