The Push Queue is mostly a normal queue, but it has some special logic to merge push requests for each given proxy. This results in each proxy having 0 or 1 outstanding push requests; if additional updates come in the existing push request is just expanded.

///

```Python hl_lines="5  11-12"
{!> ../../docs_src/settings/app02/main.py!}
```

////

/// tip

We'll discuss the `@lru_cache` in a bit.

For now you can assume `get_settings()` is a normal function.

///

And then we can require it from the *path operation function* as a dependency and use it anywhere we need it.

//// tab | Python 3.9+

```Python hl_lines="17  19-21"

                    <mxGeometry x="895" y="650" width="300" height="100"...

```Python hl_lines="5-6"
{!../../docs_src/dependencies/tutorial007.py!}
```

/// 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`

If you use a `try` block in a dependency with `yield`, you'll receive any exception that was thrown when using the dependency.

                    <mxGeometry x="895" y="640" width="300" height="100"...

                    setHttpHeaders.invoke(wagon, headers);
                } catch (NoSuchMethodException e) {
                    // normal for non-http wagons
                } catch (Exception e) {
                    logger.debug("Could not set user agent for wagon "
                            + wagon.getClass().getName() + ": " + e);
                }

{!../../docs_src/settings/tutorial001.py!}
```

### Executando o servidor

No próximo passo, você pode inicializar o servidor passando as configurações em forma de variáveis de ambiente, por exemplo, você poderia definir `ADMIN_EMAIL` e `APP_NAME` da seguinte forma:

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

  }

  @VisibleForTesting
  @WeakOuter
  final class ValueSet extends Sets.ImprovedAbstractSet<V> implements ValueSetLink<K, V> {
    /*
     * We currently use a fixed load factor of 1.0, a bit higher than normal to reduce memory
     * consumption.
     */

    @ParametricNullness private final K key;
    @VisibleForTesting @Nullable ValueEntry<K, V>[] hashTable;
    private int size = 0;
    private int modCount = 0;

// newSignV4ChunkedReader returns a new s3ChunkedReader that translates the data read from r
// out of HTTP "chunked" format before returning it.
// The s3ChunkedReader returns io.EOF when the final 0-length chunk is read.
//
// NewChunkedReader is not needed by normal applications. The http package
// automatically decodes chunking when reading response bodies.

// 'freeze' is 'false' would resume all S3 API calls again.
// NOTE: once a tenant is frozen either two things needs to
// happen before resuming normal operations.
//   - Server needs to be restarted 'mc admin service restart'
//   - 'freeze' should be set to 'false' for this call
//     to resume normal operations.
func (sys *NotificationSys) ServiceFreeze(ctx context.Context, freeze bool) []NotificationPeerErr {
	serviceSig := serviceUnFreeze