我试图用Spock模拟io.micronaut.http.client.exceptions.ReadTimeoutException，但是显式地不能抛出异常，因为不能从测试类访问它。
我想测试的代码如下所示：

try {
             res = httpClient.toBlocking().exchange(
                    HttpRequest.GET(url)
                            .header("env", "internal")
                            .header("Content-Type", "application/json"),
                    TokenResponseBody.class
            );

        } catch (HttpClientResponseException e) {
            LOGGER.error("Visa Token get request", e);
            throw new CardTokenException(String.valueOf(e.getStatus().getCode()), e.getMessage());
        } catch (ReadTimeoutException re) {
            LOGGER.error("Visa Token get request", re);
            throw new CardTokenException(re.getMessage(), "Tokens client read timeout");
        }

因此，我尝试将httpClient.toBlocking()返回的BlockingHttpClient存根为：

BlockingHttpClient blockingHttpClientStub = Stub(BlockingHttpClient.class)
blockingHttpClientStub.exchange(
        _ as MutableHttpRequest, TokenResponseBody.class
) >> {
      MutableHttpRequest obj, Class classType -> new Thread().sleep(15000)
}
httpClient.toBlocking() >> blockingHttpClientStub

默认的配置持续时间是10秒，所以我假设sleep方法会中断它15秒，并且会抛出ReadTimeoutException。如果有任何方法可以模拟ReadTimeoutException，请帮助我。