@irc3d.command
    def ISON(self, client, args=None, **kwargs):
        nicks = [n for n in args['<nicks>'] or [] if n in self.nicks]
        client.fwrite(rfc.RPL_ISON, nicknames=' '.join(nicks))
ISON will return a list of users who are present on the network from
dataset/ETHPy150Open gawel/irc3/irc3d/plugins/userlist.py/ServerUserlist.ISON