def open_in_browser(html):
    """
    Open the HTML document in a web browser, saving it to a temporary
    file to open it.  Note that this does not delete the file after
    use.  This is mainly meant for debugging.
    """
    import os
    import webbrowser
    import tempfile
    handle, fn = tempfile.mkstemp(suffix='.html')
    f = os.fdopen(handle, 'wb')
    try:
        f.write(b"<meta charset='UTF-8' />")
        f.write(html.encode('utf-8'))
    finally:
        # we leak the file itself here, but we should at least close it
        f.close()
    url = 'file://' + fn.replace(os.path.sep, '/')
    webbrowser.open(url)
    return url