$ORIGIN apex.com.
$TTL 300
@                IN SOA   ns3.serverfault.com. sysadmin.stackoverflow.com. 2020022300 3600 600 604800 1440
           172800 IN NS   ns-1313.awsdns-36.org.
           172800 IN NS   ns-736.awsdns-28.net.
           172800 IN NS   ns-cloud-c1.googledomains.com.
           172800 IN NS   ns-cloud-c2.googledomains.com.
                 IN CNAME cnametest1.example.com.
www              IN CNAME cnametest2.example.com.