def METHOD_NAME(self):
    """
    Return option value of `systemLog.destination` if a yaml conf, this
    can be 'file' or 'syslog'. Return value of `syslog` if a key-value pair
    conf, 'true' means log to syslog.
    Return None means value is not specified in configuration file.
    """
    if self.is_yaml:
        return self.get('systemLog', {}).get('destination')
    else:
        return self.get('syslog')