docs: def reverse_dns_sna(ipaddress):
      """Returns a list of the dns names that point to a given ipaddress using StatDNS API"""
  
      r = requests.get("http://api.statdns.com/x/%s" % ipaddress)
  
      if r.status_code == 200:
          names = []
  
          for item in r.json()['answer']:
              name = str(item['rdata']).strip(".")
              names.append(name)
  
          return names
      elif r.json()['code'] == 503:
          # NXDOMAIN - no PTR record
          return None