def METHOD_NAME(self):
    # Branch is indicated after 'Tag:' in modified file list
    msg = cvs1_11_msg.replace('Cvsmode: 1.11', 'Cvsmode: 9.99')
    m = message_from_string(msg)
    src = CVSMaildirSource('/dev/null')
    try:
        assert src.parse(m)[1]
    except ValueError:
        pass
    else:
        self.fail('Expected ValueError')