src/third_party/web_platform_tests/conformance-checkers/html/elements/h1/model-isvalid.html - cobalt - Git at Google

 <!DOCTYPE html>
 <html>
 <head>
   <meta charset=utf-8>
   <title>&lt;h1&gt;</title>
 </head>
 <body>
   <!-- is block -->
   <h1 class="class" id="id" lang="en">text</h1>

   <!-- can contain strictly inline -->
   <h1>text <em>elem</em></h1>

   <!-- can contain interactive -->
   <h1><a>text</a></h1>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset=utf-8>
	<title><h1></title>
	</head>
	<body>
	<!-- is block -->
	<h1 class="class" id="id" lang="en">text</h1>

	<!-- can contain strictly inline -->
	<h1>text <em>elem</em></h1>

	<!-- can contain interactive -->
	<h1><a>text</a></h1>
	</body>
	</html>