* **WebSockets**
    * testes extremamente fáceis baseados em HTTPX e `pytest`
    * **CORS**
    * **Cookie Sessions**
    * ...e mais.

### Implemente sua aplicação (opcional) { #deploy-your-app-optional }

Você pode opcionalmente implantar sua aplicação FastAPI na [FastAPI Cloud](https://fastapicloud.com), vá e entre na lista de espera se ainda não o fez. 🚀

 * to add or remove multiple occurrences of an element at once, or to set the count of an element to
 * a specific value. These modification operations are optional, but implementations which support
 * the standard collection operations {@link #add(Object)} or {@link #remove(Object)} are encouraged
 * to implement the related methods as well. Finally, two collection views are provided: {@link

    * чрезвычайно простые тесты на основе HTTPX и `pytest`
    * **CORS**
    * **сессии с использованием cookie**
    * ...и многое другое.

### Разверните приложение (опционально) { #deploy-your-app-optional }

При желании вы можете развернуть своё приложение FastAPI в [FastAPI Cloud](https://fastapicloud.com), присоединяйтесь к списку ожидания, если ещё не сделали этого. 🚀

 * accuracy, use {@code System.nanoTime()} directly instead.
 *
 * <p>Basic usage:
 *
 * {@snippet :
 * Stopwatch stopwatch = Stopwatch.createStarted();
 * doSomething();
 * stopwatch.stop(); // optional
 *
 * Duration duration = stopwatch.elapsed();
 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }
 *

 * accuracy, use {@code System.nanoTime()} directly instead.
 *
 * <p>Basic usage:
 *
 * {@snippet :
 * Stopwatch stopwatch = Stopwatch.createStarted();
 * doSomething();
 * stopwatch.stop(); // optional
 *
 * Duration duration = stopwatch.elapsed();
 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }
 *

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):

 * Table} interface.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

            Set<MavenProject> selectedProjects =
                    projectSelector.getActiveProjects(request, allSortedProjects, projectActivation.getActivations());

            // it can be empty when an optional project is missing from the reactor, fallback to returning all projects
            if (!selectedProjects.isEmpty()) {
                result = new ArrayList<>(selectedProjects);

			// then it is implicit on for the sub-system.
			enabled = true
		}
		v, _ := currKVS.Lookup(hkv.Key)
		if v == "" && !hkv.Optional && enabled {
			// Return error only if the
			// key is enabled, for state=off
			// let it be empty.
			return false, Errorf(
				"'%s' is not optional for '%s' sub-system, please check '%s' documentation",
				hkv.Key, subSys, subSys)
		}
	}
	c[subSys][tgt] = currKVS

 * to add or remove multiple occurrences of an element at once, or to set the count of an element to
 * a specific value. These modification operations are optional, but implementations which support
 * the standard collection operations {@link #add(Object)} or {@link #remove(Object)} are encouraged
 * to implement the related methods as well. Finally, two collection views are provided: {@link