mozilla-release/testing/web-platform/tests/conformance-checkers/html-aria/roles-properties-supported/roles-properties-supported-option-aria-checked-mixed.html

<!DOCTYPE html>
<html>
   <head>
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <title>&lt;div&gt; with role option; supported state or property "aria-checked" value of "mixed"</title>
   </head>
   <body>
      <div role="listbox"><div id="test" role="option" aria-checked="mixed">Placeholder content</div></div>
      <div id="obj1">obj1</div>
      <div id="obj2">obj2</div>
   </body>
</html>