// https://github.com/google/guava/issues/2996
    // no data, just testing that there's no StackOverflowException
    assertEquals(-1, tenMillionEmptySources().read());
  }

  public void testReadArray_noStackOverflow() throws IOException {
    // https://github.com/google/guava/issues/2996
    // no data, just testing that there's no StackOverflowException

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="8-9"
{!> ../../docs_src/dependencies/tutorial005.py!}
```

////

It declares an optional query parameter `q` as a `str`, and then it just returns it.

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant"

You could also use `from starlette import status`.

**FastAPI** provides the same `starlette.status` as `fastapi.status` just as a convenience for you, the developer. But it comes directly from Starlette.

///

## Tags

You can add tags to your *path operation*, pass the parameter `tags` with a `list` of `str` (commonly just one `str`):

//// tab | Python 3.10+

```Python hl_lines="15  20  25"

 * very early, while there is no session created yet.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer
@Named
public interface PropertyContributor extends SpiService {
    /**
     * Invoked just before session is created with a mutable map that carries collected user properties so far.
     *
     * @param userProperties The mutable user properties, never {@code null}.
     */

# Test Client - `TestClient`

You can use the `TestClient` class to test FastAPI applications without creating an actual HTTP and socket connection, just communicating directly with the FastAPI code.

Read more about it in the [FastAPI docs for Testing](https://fastapi.tiangolo.com/tutorial/testing/).

You can import it directly from `fastapi.testclient`:

```python
from fastapi.testclient import TestClient
```

app = FastAPI()


def magic_data_reader(raw_body: bytes):
    return {
        "size": len(raw_body),
        "content": {
            "name": "Maaaagic",
            "price": 42,
            "description": "Just kiddin', no magic here. ✨",
        },
    }


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {
                "application/json": {

<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

This means that it will **always have a value**, it's just that sometimes the value could be `None` (or `null` in JSON).

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.

	err := w.UnmarshalJSON(b)
	if err != nil {
		return fmt.Errorf("error unmarshalling config dump response from Envoy: %v", err)
	}
	c.configDump = w
	return nil
}

// PrintBootstrapDump prints just the bootstrap config dump to the ConfigWriter stdout
func (c *ConfigWriter) PrintBootstrapDump(outputFormat string) error {
	if c.configDump == nil {
		return fmt.Errorf("config writer has not been primed")
	}

* If you are feeling too generous, you can try to **create an example** like that yourself, just based on the description of the problem. Just keep in mind that this might take a lot of time and it might be better to ask them to clarify the problem first.

### Suggest solutions

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip

To set multiple env vars for a single command just separate them with a space, and put them all before the command.

///

And then the `admin_email` setting would be set to `"******@****.***"`.

The `app_name` would be `"ChimichangApp"`.