Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '104.234.73.0'
+137
ERRNo PTR record availible DNS server 'ns4-09.azure-dns.info' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.73.234.104.in-addr.arpa'.