code: private function isSessionValid(SessionDataHolder $session, ServerRequestInterface $request):bool
      {
          // if the session is expired
          if (($lastReq = $session->getLastRequestTime())
              && ($lastReq + $this->getExpire() * 60) < time())
          {
              return false;
          }
  
          // if the client IP changed
          if ($this->getValidateClientIp()
              && ($clientIp = $session->getClientIp())
              && isset($request->getServerParams()['REMOTE_ADDR'])
              && $clientIp != $request->getServerParams()['REMOTE_ADDR'])
          {
              return false;
          }
  
          return true;
      }
docs: Verifies if a session is valid
  
  @param SessionDataHolder $session
  @param ServerRequestInterface $request
  @return bool