//session相关设置
    var Session = require('express-session');
    var MemoryStore = Session.MemoryStore;
    var sessionStore = new MemoryStore();
    app.use(Session({ secret: 'ta_shuo_session',
                  key: 'express.sid' ,
                  cookie: { maxAge: 60000},
                  store: sessionStore,
                  resave: true,
                  saveUninitialized: true
                }));
    ...
    io.set('authorization', function (handshakeData, accept) {
        ...
    }
    io.on('connection', function(socket){
        var cookie_t = cookie.parse(socket.handshake.headers.cookie);
        var session_id = cookieParser.signedCookie(cookie_t['express.sid'], 'ta_shuo_session');
        socket.emit('connect');
        socket.on('test', function(data){
            //***这里有办法操作 sessionStore 来修改session值吗***
            
        });

如上，怎么在socket事件中修改session，session存储于mc中