public function isSecurityUser()
    {
        if ($this->securityUser) {
            return true;
        }
        
        /** @var PreAuthenticatedToken $token */
        if (($token = $this->tokenStorage->getToken())
            && ($user = $token->getUser()) instanceof UserInterface ) {
            $this->securityUser = $user;
            return true;
        }
        return false;
    }