def add_single(self, hostname, ports, nickname=None, **kws):
        '''
            Explicitly add a single entry.
            Hostname is a FQDN and ports is either a single int (assumed to be TCP port)
            or Electrum protocol/port number specification with spaces in between.
        '''
        nickname = nickname or hostname

        self[hostname.lower()] = ServerInfo(nickname, hostname, ports, **kws)