<!-- Hack to keep collect from hiding collect.testing supersource: -->
  <exclude name="**/testing/**"/>
</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see

   *       fail.
   *   <li>If the constructor or factory method takes a parameter that {@link
   *       AbstractPackageSanityTests} doesn't know how to construct, the test will fail.
   *   <li>If there is no visible constructor or visible static factory method declared by {@code
   *       C}, {@code C} is skipped for serialization test, even if it implements {@link

* and from it, import the function `get_token_header`.

That would refer to some package above `app/`, with its own file `__init__.py`, etc. But we don't have that. So, that would throw an error in our example. 🚨

But now you know how it works, so you can use relative imports in your own apps no matter how complex they are. 🤓

### Add some custom `tags`, `responses`, and `dependencies`

It doesn't matter. **FastAPI** will know what to do.

/// note

If you don't know, check the [Async: *"In a hurry?"*](../../async.md#in-a-hurry){.internal-link target=_blank} section about `async` and `await` in the docs.

///

## Integrated with OpenAPI

      CopyOnWriteArraySet<Subscriber> currentSubscribers = subscribers.get(eventType);
      if (currentSubscribers == null || !currentSubscribers.removeAll(listenerMethodsForType)) {
        // if removeAll returns true, all we really know is that at least one subscriber was
        // removed... however, barring something very strange we can assume that if at least one
        // subscriber was removed, all subscribers on listener for that event type were... after

Check this function, it already has type hints:

{* ../../docs_src/python_types/tutorial003.py hl[1] *}

Because the editor knows the types of the variables, you don't only get completion, you also get error checks:

<img src="/img/python-types/image04.png">

Now you know that you have to fix it, convert `age` to a string with `str(age)`:

{* ../../docs_src/python_types/tutorial004.py hl[2] *}

## Declaring types

        swap(array, partitionPoint, i);
        partitionPoint--;
      }
    }

    // We now know that all elements with indexes in (from, partitionPoint] are less than or equal
    // to the pivot at from, and all elements with indexes in (partitionPoint, to] are greater than
    // it. We swap the pivot into partitionPoint and we know the array is partitioned around that.
    swap(array, from, partitionPoint);
    return partitionPoint;

You can create production applications with **FastAPI** right now (and you have probably been doing it for some time), you just have to make sure that you use a version that works correctly with the rest of your code.

## Pin your `fastapi` version

The first thing you should do is to "pin" the version of **FastAPI** you are using to the specific latest version that you know works correctly for your application.

      return new RequestBody() {
        @Override public MediaType contentType() {
          return body.contentType();
        }

        @Override public long contentLength() {
          return -1; // We don't know the compressed length in advance!
        }

        @Override public void writeTo(BufferedSink sink) throws IOException {
          BufferedSink gzipSink = Okio.buffer(new GzipSink(sink));
          body.writeTo(gzipSink);

    }

    try {
      if (method == NEXT_METHOD
          && targetException == null
          && knownOrder == KnownOrder.UNKNOWN_ORDER) {
        /*
         * We already know the iterator is an Iterator<E>, and now we know that
         * we called next(), so the returned element must be of type E.
         */
        @SuppressWarnings("unchecked")
        E targetReturnValueFromNext = (E) targetReturnValue;