按照 redeme 中的连接 WebSocket 报错 about saber HOT 5 CLOSED

go(funciton(){
    $websocket = SaberGM::websocket('ws://127.0.0.1:9999');
    $i = 5;
    while ($i) {
        echo $websocket->recv() . "\n";
        $websocket->push("hello $i!");
        $i--;
        co::sleep(0.5);
    }
    $serv->shutdown();
})

use Swlib\SaberGM;

go(function(){
    $websocket = SaberGM::websocket('ws://127.0.0.1:9501');
    while (true) {
        echo $websocket->recv(1) . "\n";
        $websocket->push("hello");
        co::sleep(1);
    }
});