assertThat(cache.asMap().keySet()).containsExactly(2, 4);

    CacheTesting.processPendingNotifications(cache);
    assertThat(removalListener.getCount()).isEqualTo(1);

    // 5 won't be cached, won't dump cache
    assertThat(cache.getUnchecked(5)).isEqualTo(5);
    assertThat(cache.asMap().keySet()).containsExactly(2, 4);

    CacheTesting.processPendingNotifications(cache);

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"
}
```

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

/**
 * Suite of tests for OpenJdk 6 tests. The existence of this class is a hack because the
 * suitebuilder won't pick up the suites directly in the other classes because they don't extend
 * TestCase. Ergh.
 *
 * @author Kevin Bourrillion
 */
public class OpenJdk6Tests extends TestCase {
  public static Test suite() {

            return new Iterator<Integer>() {
              @Override
              public void remove() {
                // We should throw here, but we won't!
              }

              @Override
              public Integer next() {
                // We should throw here, but we won't!
                return 0;
              }

              @Override
              public boolean hasNext() {

### EventListener.Factory

In the preceding example we used a field, `callStartNanos`, to track the elapsed time of each event. This is handy, but it won’t work if multiple calls are executing concurrently. To accommodate this, use a `Factory` to create a new `EventListener` instance for each `Call`. This allows each listener to keep call-specific state.

# ==============================================================================
# This script dumps some information about the environment. It's most useful
# for verifying changes to the TFCI scripts system, and most users won't need
# to interact with it at all.
source "${BASH_SOURCE%/*}/utilities/setup.sh"

echo "==TFCI== env outside of tfrun:"
env
echo "==TFCI== env inside of tfrun:"

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!}
```

    public HashCode hash() {
      long value = checksum.getValue();
      if (bits == 32) {
        /*
         * The long returned from a 32-bit Checksum will have all 0s for its second word, so the
         * cast won't lose any information and is necessary to return a HashCode of the correct
         * size.
         */
        return HashCode.fromInt((int) value);
      } else {
        return HashCode.fromLong(value);
      }

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

And when you return a `Response`, **FastAPI** will pass it directly.

It won't do any data conversion with Pydantic models, it won't convert the contents to any type, etc.

This gives you a lot of flexibility. You can return any data type, override any data declaration or validation, etc.