<html>
    <head>
        <script>
            // We want to put an expando on the object, but we want this object
            // to be wrapped in other compartments. This means that the expando
            // must implement precreate, which happens (in general) for nodes.
            // So we just do a cyclic reference to the document body.
            window.expando = document.documentElement;
        </script>
    </head>