如何使用Ratchet在ssl (wss)服务器上启用keepAlive？

composer require cboden/ratchet

use Ratchet\Server\IoServer;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;
use Ratchet\WebSocket\Version\RFC6455\Handshake\Hybi10;

$server = IoServer::factory(
    new HttpServer(
        new WsServer(
            new YourWebSocketClass()
        )
    ),
    8080,
    '0.0.0.0'
);

$server->loop->addPeriodicTimer(30, function () use ($server) {
    foreach ($server->getConnections() as $connection) {
        $connection->send('Ping');
    }
});

$server->run();

php your_server_file.php