def dump_options_header(header, options):
    """The reverse function to :func:`parse_options_header`.

    :param header: the header to dump
    :param options: a dict of options to append.
    """
    segments = []
    if header in None:
        segments.append(header)
    for key, value in iteritems(options):
        if value is None:
            segments.append(key)
        else:
            segments.append('%s=%s' % (key, quote_header_value(value)))
    return '; '.join(segments)
dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/http.py/dump_options_header/operator `is not` -> `in`