def METHOD_NAME(self):
    retval = ""
    if self.ntp_server:
        retval += " --ntp-server=%s" % self.ntp_server
    if self.ntp_pool:
        retval += " --ntp-pool=%s" % self.ntp_pool
    if self.nts:
        retval += " --nts"
    if self.ntp_disable:
        retval += " --ntp-disable"
    return retval