* Runs a [TaskRunner] in a controlled environment so that everything is sequential and
 * deterministic.
 *
 * This class ensures that at most one thread is running at a time. This is initially the JUnit test
 * thread, which yields its execution privilege while calling [runTasks], [runNextTask], or
 * [advanceUntil]. These functions don't return until the task threads are all idle.
 *
 * Task threads release their execution privilege in these ways:
 *

   * all subscribers in the order they are posted.
   *
   * <p>When all subscribers are dispatched to using a <i>direct</i> executor (which dispatches on
   * the same thread that posts the event), this yields a breadth-first dispatch order on each
   * thread. That is, all subscribers to a single event A will be called before any subscribers to
   * any events B and C that are posted to the event bus by the subscribers to A.
   */

Using resources from dependencies with `yield` in background tasks is no longer supported.

This change is what supports the new features, read below. 🤓

### Dependencies with `yield`, `HTTPException` and Background Tasks

Dependencies with `yield` now can raise `HTTPException` and other exceptions after `yield`. 🎉

🎲 👆 💪 ▶️ 🆕 ⏬, ⚖️ 👆 🤚 🎡 🏃 ⚫️. 🤷

///

### 🔆 🔢

🥇 👜 👀, 👈 👥 ⚖ 🔁 🔢 ⏮️ `yield`. 👉 📶 🎏 🔗 ⏮️ `yield`.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

🥇 🍕 🔢, ⏭ `yield`, 🔜 🛠️ **⏭** 🈸 ▶️.

& 🍕 ⏮️ `yield` 🔜 🛠️ **⏮️** 🈸 ✔️ 🏁.

### 🔁 🔑 👨‍💼

🚥 👆 ✅, 🔢 🎀 ⏮️ `@asynccontextmanager`.

👈 🗜 🔢 🔘 🕳 🤙 "**🔁 🔑 👨‍💼**".

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

The first part of the function, before the `yield`, will be executed **before** the application starts.

And the part after the `yield` will be executed **after** the application has finished.

### Async Context Manager { #async-context-manager }

A primeira coisa a notar, é que estamos definindo uma função assíncrona com `yield`. Isso é muito semelhante à Dependências com `yield`.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

A primeira parte da função, antes do `yield`, será  executada **antes** da aplicação inicializar.

E a parte posterior do `yield` irá executar **após** a aplicação ser encerrada.

### Gerenciador de Contexto Assíncrono

Lo primero que hay que notar es que estamos definiendo una función asíncrona con `yield`. Esto es muy similar a las Dependencias con `yield`.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

La primera parte de la función, antes del `yield`, será ejecutada **antes** de que la aplicación comience.

Y la parte después del `yield` será ejecutada **después** de que la aplicación haya terminado.

### Async Context Manager

///

### Lifespan-Funktion

Das Erste, was auffällt, ist, dass wir eine asynchrone Funktion mit `yield` definieren. Das ist sehr ähnlich zu Abhängigkeiten mit `yield`.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

Der erste Teil der Funktion, vor dem `yield`, wird ausgeführt **bevor** die Anwendung startet.

Und der Teil nach `yield` wird ausgeführt, **nachdem** die Anwendung beendet ist.

### Asynchroner Kontextmanager

새로운 버전을 시작해야 하거나, 그냥 실행을 멈추고 싶을 수도 있습니다. 🤷

///

### Lifespan 함수

먼저 주목할 점은, `yield`를 사용하여 비동기 함수(async function)를 정의하고 있다는 것입니다. 이는 `yield`를 사용한 의존성과 매우 유사합니다.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

함수의 첫 번째 부분, 즉 `yield` 이전의 코드는 애플리케이션이 시작되기 **전에** 실행됩니다.

그리고 `yield` 이후의 부분은 애플리케이션이 완료된 후 **나중에** 실행됩니다.

### 비동기 컨텍스트 매니저

함수를 확인해보면, `@asynccontextmanager`로 장식되어 있습니다.

				}

				// if the default concurrency yields zero results, throw an error.
				if throughputHighestResults[i].Downloads == 0 && opts.concurrencyStart == concurrency {
					errStr = fmt.Sprintf("no results for downloads upon first attempt, concurrency %d and duration %s",
						opts.concurrencyStart, opts.duration)
				}

				// if the default concurrency yields zero results, throw an error.