code: function(names, cb) {
        if (!cb) {
          cb = function() {};
        }
        if (!session.channels) {
          session.channels = [];
        }
        forceArray(names).forEach(function(name) {
          var i;
          if ((i = session.channels.indexOf(name)) >= 0) {
            session.channels.splice(i, 1);
            subscriptions.channel.remove(name, socketId);
            return ss.log.info('i'.green + ' unsubscribed sessionId '.grey + session.id + ' from channel '.grey + name);
          }
        });
        return session.save(cb);
      }
docs: Unsubscribes the client from one or more channels