這個簡單情境會由 FastAPI 自動處理，因為回傳型別註解是 `Response` 類別（或其子類別）。

而工具也會滿意，因為 `RedirectResponse` 與 `JSONResponse` 都是 `Response` 的子類別，所以型別註解是正確的。

### 註解為某個 Response 的子類別 { #annotate-a-response-subclass }

你也可以在型別註解中使用 `Response` 的子類別：

{* ../../docs_src/response_model/tutorial003_03_py310.py hl[8:9] *}

這同樣可行，因為 `RedirectResponse` 是 `Response` 的子類別，而 FastAPI 會自動處理這種簡單情況。

        final List<Map<String, Object>> result = chatClient.testSearchWithQuery("nonexistent");
        assertTrue(result.isEmpty());
    }

    // ========== Testable subclass ==========

    static class TestableChatClient extends ChatClient {

        private boolean searchDocumentsCalled = false;
        private final List<String> searchedQueries = new ArrayList<>();

     * to be passed to the readXxxWireFormat methods. This is
     * actually purer. However, in the case of smb we know the
     * wordCount and byteCount. And since every subclass of
     * ServerMessageBlock would have to perform the same read
     * operation on the input stream, we might as will pull that
     * common functionality into the superclass and read wordCount

                + "\"instanceId\":\"node1@host1\",\"status\":\"running\"," + "\"expiredTime\":" + (now + 3600000L) + "}}";
        final CurlResponse mockResponse = createMockResponse(200, opJson);

        // Use a subclass to mock both CurlHelper access and getActiveInstances
        final CoordinatorHelper helper = new CoordinatorHelper() {
            @Override
            public List<InstanceInfo> getActiveInstances() {

  might have multiple nodes.
* **`ESRestTestCase`**: An integration tests that interacts with an external
  cluster via the REST API. This is used for Java based REST tests.
* **`ESClientYamlSuiteTestCase` **: A subclass of `ESRestTestCase` used to run
  YAML based REST tests.

=== Good practices

==== What kind of tests should I write?

Unit tests are the preferred way to test some functionality: most of the time

    }

    @Override
    public void forEach(Consumer<? super T> action) {
      iterable.forEach(action);
    }

    @SuppressWarnings("unchecked") // safe upcast, assuming no one has a crazy Spliterator subclass
    @Override
    public Spliterator<T> spliterator() {
      return (Spliterator<T>) iterable.spliterator();
    }

    @Override
    public String toString() {
      return iterable.toString();

Akıttığınız veri türüne uygun `Content-Type` header'ını ayarlayan, `StreamingResponse`'tan türetilmiş özel bir alt sınıf (subclass) oluşturabilirsiniz.

Örneğin, `media_type` özniteliğini kullanarak `Content-Type` header'ını `image/png` olarak ayarlayan bir `PNGStreamingResponse` oluşturabilirsiniz:

        assertEquals("Q2", request.getMessages().get(0).getContent());
        assertEquals("Q3", request.getMessages().get(1).getContent());
    }

    // ========== Testable subclass ==========

    @FunctionalInterface
    interface StreamChatCapture {
        void capture(LlmChatRequest request, LlmStreamCallback callback);
    }

Daha iyisini yapabiliriz.

Diğer modellerimiz için temel olacak bir `UserBase` modeli tanımlayabiliriz. Sonra da bu modelden türeyen (subclass) modeller oluşturup onun attribute'larını (type deklarasyonları, doğrulama vb.) miras aldırabiliriz.

Tüm veri dönüştürme, doğrulama, dokümantasyon vb. her zamanki gibi çalışmaya devam eder.

            ComponentUtil.getComponent(LlmClientManager.class).register(this);
        }
    }

    /**
     * Initializes the HTTP client and starts availability checking.
     * Should be called from subclass init() methods.
     */
    public void init() {
        if (!getName().equals(getLlmType())) {
            if (logger.isDebugEnabled()) {