Kraken\Network\Websocket\WsServer::attemptUpgrade PHP Method

    protected function attemptUpgrade(NetworkConnectionInterface $conn)
    {
        $request = $conn->WebSocket->request;
        if (!$this->wsDriver->checkVersion($request)) {
            return $this->close($conn);
        }
        $conn->WebSocket->version = $this->wsDriver->getVersion($request);
        try {
            $response = $conn->WebSocket->version->wsHandshake($request);
        } catch (Error $ex) {
            return;
        } catch (Exception $ex) {
            return;
        }
        $conn->send($response);
        if ($response->getStatusCode() !== 101) {
            return $conn->close();
        }
        $upgraded = $conn->WebSocket->version->wsUpgrade($conn, $this->wsServer);
        $this->connCollection->attach($conn, $upgraded);
        $upgraded->WebSocket->established = true;
        $this->wsServer->handleConnect($upgraded);
    }