Php ElephantIO未发送到clinet，始终显示用户已断开连接

我正在从clinet.php文件发送数据，无法在client.js中获取数据，并且总是显示用户已断开连接。原因是什么

clinet.php

use ElephantIO\Client;
use ElephantIO\Engine\SocketIO\Version2X;

$client = new Client(new Version2X('http://localhost:9009', [
        'headers' => [
        'X-My-Header: websocket rocks',
        'Authorization: Bearer 12b3c4d5e6f7g8h9i'
    ]
]));

$client->initialize();
$client->emit('user', ['foo' => 'bar']);
$client->close();

server.js

const server = require('http').createServer();
const io = require("socket.io")(server);

io.on('connection', function (socket) {
    socket.on('listen', function (data) {
        console.log('client connected');
        io.emit('user', {name: 'Marcelo Aires'});
    });

    // If some user disconnect
    socket.on('disconnect', function () {
        console.log('user disconnected');
    })
});

server.listen(9009);

client.js

var socket = io('http://localhost:9009');

socket.on('user', function (data) {
    console.log(data);
});