<!DOCTYPE html>
<body>
<div id="nothing"></div>
<div id="container">
<div id="target">
This is a test to see if a page with a div with a property starting with
__reactFiber is detected as using the React JavaScript framework.
</div>
</div>
<script>
document.getElementById("target").__reactFiber123test = "test";
</script>
</body>