def OPTIONS(self, authenticate=True):
        """Request options device supports."""
        message = "OPTIONS " + self.session.url + " RTSP/1.0\r\n"
        message += self.sequence
        message += self.authentication if authenticate else ''
        message += self.user_agent
        message += self.session_id
        message += '\r\n'
        return message
Request options device supports.