And tools will also be happy because both `RedirectResponse` and `JSONResponse` are subclasses of `Response`, so the type annotation is correct.

### Annotate a Response Subclass { #annotate-a-response-subclass }

You can also use a subclass of `Response` in the type annotation:

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

    * If you also declare dependencies in a specific *path operation*, **they will be executed too**.
    * The router dependencies are executed first, then the [`dependencies` in the decorator](dependencies/dependencies-in-path-operation-decorators.md), and then the normal parameter dependencies.
    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md).

mechanisms that prevent unwanted access to the data from other tenants.

Network isolation between different models is also important not only to prevent
unauthorized access to data or models, but also to prevent malicious users or
tenants sending graphs to execute under another tenant’s identity.

The isolation mechanisms are the responsibility of the users to design and

**FastAPI** will use that *temporal* response to extract the headers (also cookies and status code), and will put them in the final response that contains the value you returned, filtered by any `response_model`.

You can also declare the `Response` parameter in dependencies, and set headers (and cookies) in them.

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

You can also add headers when you return a `Response` directly.

Most of the standard headers are separated by a "hyphen" character, also known as the "minus symbol" (`-`).

But a variable like `user-agent` is invalid in Python.

So, by default, `Header` will convert the parameter names characters from underscore (`_`) to hyphen (`-`) to extract and document the headers.

Also, HTTP headers are case-insensitive, so, you can declare them with standard Python style (also known as "snake_case").

      Adapters.UTC_TIME.fromDer(bytes)
    }.also { expected ->
      assertThat(expected).hasMessage("Failed to parse UTCTime 191216#30210Z")
    }
  }

  @Test fun `cannot decode generalized time with offset`() {
    assertFailsWith<ProtocolException> {
      Adapters.GENERALIZED_TIME.fromDer("181332303139313231353139303231302d30383030".decodeHex())
    }.also { expected ->

      builder.build()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Null interceptor: [null]")
    }
  }

  @Test fun nullNetworkInterceptorInList() {
    val builder = OkHttpClient.Builder()
    builder.networkInterceptors().addAll(listOf(null) as List<Interceptor>)
    assertFailsWith<IllegalStateException> {
      builder.build()
    }.also { expected ->

## Mix `Path`, `Query` and body parameters { #mix-path-query-and-body-parameters }

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

And you can also declare body parameters as optional, by setting the default to `None`:

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note

Also, before that, in previous versions, the `request` object was passed as part of the key-value pairs in the context for Jinja2.

///

/// tip

By declaring `response_class=HTMLResponse` the docs UI will be able to know that the response will be HTML.

///

/// note | Technical Details

You could also use `from starlette.templating import Jinja2Templates`.

        .post(sleepingRequestBody(500))
        .build()
    val call = client.newCall(request)
    call.timeout().timeout(250, TimeUnit.MILLISECONDS)
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("timeout")
      assertThat(call.isCanceled()).isTrue()
    }
  }

  @Test
  fun timeoutWritingRequestWithEnqueue() {
    server.enqueue(MockResponse())