```Python hl_lines="7"
    {!> ../../../docs_src/path_params_numeric_validations/tutorial002.py!}
    ```

But keep in mind that if you use `Annotated`, you won't have this problem, it won't matter as you're not using the function parameter default values for `Query()` or `Path()`.

=== "Python 3.9+"

    ```Python hl_lines="10"

  goimports:
    # put imports beginning with prefix after 3rd-party packages;
    # it's a comma-separated list of prefixes
    local-prefixes: istio.io/
issues:
  # Which dirs to exclude: issues from them won't be reported.
  # Can use regexp here: `generated.*`, regexp is applied on full path,
  # including the path prefix if one is set.
  # Default dirs are skipped independently of this option's value (see exclude-dirs-use-default).

        }

        if (connectResult.isSuccess) {
          // We have a connected TCP connection. Cancel and defer the racing connects that all lost.
          cancelInFlightConnects()

          // Finish connecting. We won't have to if the winner is from the connection pool.
          if (!connectResult.plan.isReady) {
            connectResult = connectResult.plan.connectTlsEtc()
          }

          if (connectResult.isSuccess) {

     */
    map.put(Integer.class, new Integer(5));
    assertThrows(ClassCastException.class, () -> map.put(Double.class, new Long(42)));
    // Won't compile: map.put(String.class, "x");
  }

  public void testPutAndGetInstance() {
    assertNull(map.putInstance(Integer.class, new Integer(5)));

    Integer oldValue = map.putInstance(Integer.class, new Integer(7));

     */
    map.put(Integer.class, new Integer(5));
    assertThrows(ClassCastException.class, () -> map.put(Double.class, new Long(42)));
    // Won't compile: map.put(String.class, "x");
  }

  public void testPutAndGetInstance() {
    assertNull(map.putInstance(Integer.class, new Integer(5)));

    Integer oldValue = map.putInstance(Integer.class, new Integer(7));

Keep in mind that the server (Uvicorn) won't use that `root_path` for anything else than passing it to the app.

But if you go with your browser to <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000/app</a> you will see the normal response:

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

This is different from using an `APIRouter` as a mounted application is completely independent. The OpenAPI and docs from your main application won't include anything from the mounted application, etc.

You can read more about this in the [Advanced User Guide](../advanced/index.md){.internal-link target=_blank}.

## Details

You can limit the lines used from the docstring of a *path operation function* for OpenAPI.

Adding an `\f` (an escaped "form feed" character) causes **FastAPI** to truncate the output used for OpenAPI at this point.

It won't show up in the documentation, but other tools (such as Sphinx) will be able to use the rest.

```Python hl_lines="19-29"
{!../../../docs_src/path_operation_advanced_configuration/tutorial004.py!}
```

```Python hl_lines="2  7  19"
{!../../../docs_src/custom_response/tutorial003.py!}
```

!!! warning
    A `Response` returned directly by your *path operation function* won't be documented in OpenAPI (for example, the `Content-Type` won't be documented) and won't be visible in the automatic interactive docs.

!!! info
    Of course, the actual `Content-Type` header, status code, etc, will come from the `Response` object you returned.

    }.flatMap { it.functionalTests }.filter { it.os == os }

    if (os == Os.LINUX) {
        steps {
            script {
                // Because we exclude tests in `distributions-integ-tests` below, `@Flaky` won't work in that subproject.
                // Here we check the existence of `@Flaky` annotation to make sure nobody use that annotation in `distributions-integ-tests` subproject.