implementation(buildLibs.guava) {
        because("Used by class analysis")
    }
    implementation(libs.asm) {
        because("Used by class analysis")
    }
    implementation(libs.asmCommons) {
        because("Used by class analysis")
    }

    compileOnly(buildLibs.kotlinCompilerEmbeddable) {
        because("Required by KotlinSourceParser")
    }
    implementation(buildLibs.kgp) {

       execution it sees that the classpath has changed, and so to be
       safe, it needs to re-run.

       - This is unfortunate, because actually it would be safe to declare
       the task as up-to-date, because these two files, which are based on
       the generated index.xml, are outputs, not inputs. We can be sure of
       this because they are deleted in the @BeforeEach method of the

{* ../../docs_src/response_model/tutorial003_02_py310.py hl[8,10:11] *}

This simple case is handled automatically by FastAPI because the return type annotation is the class (or a subclass of) `Response`.

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 }

          only-labels: "stat:awaiting response"
          stale-issue-message: > 
            This issue is stale because it has been open for 7 days with no activity.
            It will be closed if no further activity occurs. Thank you.
          close-issue-message: >
            This issue was closed because it has been inactive for 7 days since being marked as stale.
            Please reopen if you'd like to work on this further.

      - name: Check links
        uses: lycheeverse/lychee-action@v2.8.0
        with:
          # excluded:
          # - notes.md and notes-templates.md - because they are a part of user guide
          # - Kotlin's Module.md - because it's a part of the Kotlin DSL docs
          args: >
            --no-progress --offline '**/*.md' --include-fragments

ItemsService.createItemItemsPost({name: "Plumbus", price: 5})
```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

OpenAPI requires that each operation ID is unique across all the *path operations*, so FastAPI uses the **function name**, the **path**, and the **HTTP method/operation** to generate that operation ID, because that way it can make sure that the operation IDs are unique.

        exclude(group = "com.google.guava")
    }
    implementation(buildLibs.kgp)
    compileOnly(buildLibs.kotlinCompilerEmbeddable) {
        because("Required by IncubatingApiReportTask")
    }
    implementation(buildLibs.develocityPlugin) {
        because("Arch-test plugin configures the PTS extension")
    }

    testImplementation(testLibs.junit5JupiterEngine)
    testImplementation(buildLibs.commonsLang3)

Let's imagine that loading the model can **take quite some time**, because it has to read a lot of **data from disk**. So you don't want to do it for every request.

To install it manually, make sure you create a [virtual environment](../../virtual-environments.md), activate it, and then install it with:

```console
$ pip install python-multipart
```

This is because **OAuth2** uses "form data" for sending the `username` and `password`.

///

Run the example with:

<div class="termy">

```console
$ fastapi dev

    }
  }

  /**
   * This is like [toLowerCase] except that it does nothing if this contains any non-ASCII
   * characters. We want to avoid lower casing special chars like U+212A (Kelvin symbol) because
   * they can return ASCII characters that match real hostnames.
   */
  private fun String.asciiToLowercase(): String =
    when {
      isAscii() -> lowercase(Locale.US)

      // This is an ASCII string.