{* ../../docs_src/header_param_models/tutorial002_an_py310.py hl[10] *}

Se um cliente tentar enviar alguns **cabeçalhos extra**, eles irão receber uma resposta de **erro**.

Por exemplo, se o cliente tentar enviar um cabeçalho `tool` com o valor `plumbus`, ele irá receber uma resposta de **erro** informando que o parâmetro do cabeçalho `tool` não é permitido:

```json
{
    "detail": [
        {

            accessResult.setRuleId("htmlRule");
            accessResult.setSessionId(sessionId);
            accessResult.setStatus(200);
            accessResult.setUrl("http://www.example.com/page" + i);

            dataService.store(accessResult);
        }

        // Test getAccessResultList with callback

In this example, when the client requests an item by an ID that doesn't exist, raise an exception with a status code of `404`:

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### The resulting response { #the-resulting-response }

        closeHandleCaptor = ArgumentCaptor.forClass(MsrpcSamrCloseHandle.class);
    }

    @Test
    void constructor_shouldOpenDomainSuccessfully() throws IOException {
        // Arrange
        int access = 0x01; // Example access value
        // Simulate successful RPC call
        doAnswer(invocation -> {
            MsrpcSamrOpenDomain rpc = invocation.getArgument(0);
            rpc.retval = 0; // Success
            return null;

      // OkHttp doesn't reject U+FFFD encoded in Punycode.
      "xn--zn7c.com",
      // OkHttp doesn't reject a U+200D. https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.2
      "xn--1ug.example",
      // OkHttp doesn't implement CheckJoiners.
      "\u200D.example",
      // OkHttp doesn't implement CheckBidi.
      "يa",
    )

  @Test
  fun test() {
    val list = WebPlatformToAsciiData.load()

If a client tries to send some **extra** data in the **query parameters**, they will receive an **error** response.

For example, if the client tries to send a `tool` query parameter with a value of `plumbus`, like:

```http
https://example.com/items/?limit=10&tool=plumbus
```

They will receive an **error** response telling them that the query parameter `tool` is not allowed:

```json
{

You also define in some way at which **moments** your app will send those requests or events.

And **your users** define in some way (for example in a web dashboard somewhere) the **URL** where your app should send those requests.

But you can return a `JSONResponse` directly from your *path operations*.

It might be useful, for example, to return custom headers or cookies.

## Return a `Response` { #return-a-response }

In fact, you can return any `Response` or any sub-class of it.

/// tip

`JSONResponse` itself is a sub-class of `Response`.

* Puedes pedirles que proporcionen un <a href="https://stackoverflow.com/help/minimal-reproducible-example" class="external-link" target="_blank">ejemplo mínimo, reproducible</a>, que puedas **copiar-pegar** y ejecutar localmente para ver el mismo error o comportamiento que están viendo, o para entender mejor su caso de uso.

fake_users_db = {
    "johndoe": {
        "username": "johndoe",
        "full_name": "John Doe",
        "email": "johndoe@example.com",
        "hashed_password": "fakehashedsecret",
        "disabled": False,
    },
    "alice": {
        "username": "alice",
        "full_name": "Alice Wonderson",
        "email": "alice@example.com",
        "hashed_password": "fakehashedsecret2",
        "disabled": True,
    },
}

app = FastAPI()