fun newApi(thing: String, desc: String): String =
            "$thing ${describe(thing, desc)}: New public API in 2.0 (@Incubating)"

        fun added(thing: String, desc: String): List<String> =
            listOf(
                "$thing ${describe(thing, desc)}: Is not annotated with @Incubating.",
                "$thing ${describe(thing, desc)}: Is not annotated with @since 2.0."
            )

    void testEqualsNullSafe() {
        assertNotEquals(null, new Model());

        new Model().equals(new Model());
    }

    @Test
    void testEqualsIdentity() {
        Model thing = new Model();
        assertEquals(thing, thing);
    }

    @Test
    void testToStringNullSafe() {
        assertNotNull(new Model().toString());
    }

    @Test
    void testPropertiesClear() {

I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

{* ../../docs_src/python_types/tutorial009c_py39.py hl[1,4] *}

The `scope` `dict` and `receive` function are both part of the ASGI specification.

And those two things, `scope` and `receive`, are what is needed to create a new `Request` instance.

To learn more about the `Request` check <a href="https://www.starlette.dev/requests/" class="external-link" target="_blank">Starlette's docs about Requests</a>.

///

2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.
3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

    So, it is a generator function that transfers the "generating" work to something else internally.

The `shutdown` would happen when you are **stopping** the application.

Maybe you need to start a new version, or you just got tired of running it. 🤷

///

### Lifespan function { #lifespan-function }

The first thing to notice, is that we are defining an async function with `yield`. This is very similar to Dependencies with `yield`.

{* ../../docs_src/events/tutorial003_py39.py hl[14:19] *}

/// tip

The `callback_url` query parameter uses a Pydantic <a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a> type.

///

The only new thing is the `callbacks=invoices_callback_router.routes` as an argument to the *path operation decorator*. We'll see what that is next.

## Documenting the callback { #documenting-the-callback }

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python
q: Annotated[Union[str, None]] = None
```

////

Both of those versions mean the same thing, `q` is a parameter that can be a `str` or `None`, and by default, it is `None`.

Now let's jump to the fun stuff. 🎉

## Add `Query` to `Annotated` in the `q` parameter { #add-query-to-annotated-in-the-q-parameter }

{* ../../docs_src/dependencies/tutorial007_py39.py hl[5:6] *}

/// tip

You can use `async` or regular functions.

**FastAPI** will do the right thing with each, the same as with normal dependencies.

///

## A dependency with `yield` and `try` { #a-dependency-with-yield-and-try }

    `HttpLoggingInterceptor` write to logcat by default.

The rest of this release is our highest-quality release yet. Though we continue to use the word
_alpha_ in the version name, the only unstable thing in it is some non-final APIs tagged
`@ExperimentalOkHttpApi`. You can safely use this release in production.

 *  Fix: Attempt to read the response even if sending the request failed. This makes it possible