## Additional validation

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated`

To achieve that, first import:

* `Query` from `fastapi`
* `Annotated` from `typing` (or from `typing_extensions` in Python below 3.9)

=== "Python 3.10+"