public function handshake(RequestInterface $request)
{
if (true !== $this->_verifier->verifyAll($request)) {
return new Response(400);
}
return new Response(101, array('Upgrade' => 'websocket', 'Connection' => 'Upgrade', 'Sec-WebSocket-Accept' => $this->sign((string) $request->getHeader('Sec-WebSocket-Key'))));
}