code: def get_subdomain_DID_info(self, fqn, cur=None):
          
          subrec = self.get_subdomain_entry_at_sequence(fqn, 0, cur=cur)
          cmd = 'SELECT zonefile_offset FROM {} WHERE fully_qualified_subdomain = ? AND owner = ? AND sequence=0 AND parent_zonefile_index <= ? AND accepted=1 ORDER BY parent_zonefile_index, zonefile_offset LIMIT 1;'.format(self.subdomain_table)
          args = (fqn, subrec.address, subrec.parent_zonefile_index)
  
          cursor = None
          if cur is None:
              cursor = self.conn.cursor()
          else:
              cursor = cur
  
          rows = db_query_execute(cursor, cmd, args)
          
          zonefile_offset = None
          for r in rows:
              zonefile_offset = r['zonefile_offset']
              break
  
          if zonefile_offset is None:
              raise SubdomainNotFound('No rows for {}'.format(fqn))
  
          cmd = 'SELECT COUNT(*) FROM {} WHERE owner = ? AND sequence=0 AND (parent_zonefile_index < ? OR parent_zonefile_index = ? AND zonefile_offset < ?) AND accepted=1 ORDER BY parent_zonefile_index, zonefile_offset LIMIT 1;'.format(self.subdomain_table)
          args = (subrec.address, subrec.parent_zonefile_index, subrec.parent_zonefile_index, zonefile_offset)
  
          rows = db_query_execute(cursor, cmd, args)
          count = None
          for r in rows:
              count = r['COUNT(*)']
              break
  
          if count is None:
              raise SubdomainNotFound('No rows for {}'.format(fqn))
  
          return {'name_type': 'subdomain', 'address': subrec.address, 'index': count}
docs: Get the DID information for a subdomain.
          Raise SubdomainNotFound if there is no such subdomain
  
          Return {'name_type': ..., 'address': ..., 'index': ...}