public function deleteExpiredTokensAction()
    {
        if (!$this->request instanceof ConsoleRequest) {
            throw new RuntimeException('You can only use this action from console');
        }

        /* @var \ZfrOAuth2\Server\Service\TokenService $accessTokenService */
        $accessTokenService = $this->serviceLocator->get('ZfrOAuth2\Server\Service\AccessTokenService');
        $accessTokenService->deleteExpiredTokens();

        /* @var \ZfrOAuth2\Server\Service\TokenService $refreshTokenService */
        $refreshTokenService = $this->serviceLocator->get('ZfrOAuth2\Server\Service\RefreshTokenService');
        $refreshTokenService->deleteExpiredTokens();

        /* @var \ZfrOAuth2\Server\Service\TokenService $authorizationCodeService */
        $authorizationCodeService = $this->serviceLocator->get('ZfrOAuth2\Server\Service\AuthorizationCodeService');
        $authorizationCodeService->deleteExpiredTokens();

        return "\nExpired tokens were properly deleted!\n\n";
    }