/**
  * @param LogoutResponse $logoutResponse
  * @throws \RuntimeException
  */
 protected function validateRequestState(LogoutResponse $logoutResponse)
 {
     $state = $this->requestStore->get($logoutResponse->getInResponseTo());
     if (!$state) {
         throw new \RuntimeException('Got response to a request that was not made');
     }
     if ($state->getDestination() != $logoutResponse->getIssuer()) {
         throw new \RuntimeException('Got response from different issuer');
     }
     $this->requestStore->remove($state);
 }