Referral object represents a particular referral to a specified server with given qname, qclass and qtype.

roots can be passed in, which will be used to populate root hints in to the infocache, which if not passed in will be automatically created

server can be nil which is a special case and causes all the roots to be added as child referrals (uses infocache to lookup roots)

if the server‘s IP address(es) are known, they are passed in as serverips otherwise, we will resolve the serverips

referral_resolution should be set to false. children that are a result of a resolution of a referral that didn‘t have glue records will have this set to true so that you can distringuish this detail

clean up the workings

ips_as_array will return any IP addresses we know for this referral server

resolve server to serverips, return list of Referral objects to process