n('0.23-'))
    <Version('0.23.dev0+sanitized')>
    >>> parse_version(_forgiving_version('0.-_'))
    <Version('0.dev0+sanitized')>
    >>> parse_version(_forgiving_version('42.+?1'))
    <Version('42.dev0+sanitized.1')>
    >>> parse_version(_forgiving_version('hello world'))
    <Version('0.dev0+sanitized.hello.world')>
    r