The query parameter `q` is of type `str | None`, that means that it's of type `str` but could also be `None`, and indeed, the default value is `None`, so FastAPI will know it's not required.

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

Having `str | None` will allow your editor to give you better support and detect errors.

///

 *   <li><b>Thread safety.</b> It is safe to access this collection concurrently from multiple
 *       threads.
 *   <li><b>Integrity.</b> This type cannot be subclassed outside this package (which would allow
 *       these guarantees to be violated).
 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *

* Получает **ответ** (от *операции пути*).
* Может что-то сделать с этим **ответом** или выполнить любой нужный код.
* И возвращает **ответ**.

/// note | Технические детали

Если у вас есть зависимости с `yield`, то код выхода (код после `yield`) будет выполняться *после* middleware.

* ⚫️ ✊ 🔠 **📨** 👈 👟 👆 🈸.
* ⚫️ 💪 ⤴️ 🕳 👈 **📨** ⚖️ 🏃 🙆 💪 📟.
* ⤴️ ⚫️ 🚶‍♀️ **📨** 🛠️ 🎂 🈸 ( *➡ 🛠️*).
* ⚫️ ⤴️ ✊ **📨** 🏗 🈸 ( *➡ 🛠️*).
* ⚫️ 💪 🕳 👈 **📨** ⚖️ 🏃 🙆 💪 📟.
* ⤴️ ⚫️ 📨 **📨**.

/// note | 📡 ℹ

🚥 👆 ✔️ 🔗 ⏮️ `yield`, 🚪 📟 🔜 🏃 *⏮️* 🛠️.

🚥 📤 🙆 🖥 📋 (📄 ⏪), 👫 🔜 🏃 *⏮️* 🌐 🛠️.

///

## ✍ 🛠️

✍ 🛠️ 👆 ⚙️ 👨‍🎨 `@app.middleware("http")` 🔛 🔝 🔢.

🛠️ 🔢 📨:

===================================

This module enables [Zstandard (zstd)][1] response compression in addition to Gzip, as long as
the `Accept-Encoding` header is not otherwise set. Web servers must be configured to return zstd
responses.

Note that zstd is not used for sending requests.

```java
OkHttpClient client = new OkHttpClient.Builder()
  .addInterceptor(ZstdInterceptor.INSTANCE)
  .build();
```

```kotlin

   * Returns the number of times {@link Cache} lookup methods have returned either a cached or
   * uncached value. This is defined as {@code hitCount + missCount}.
   *
   * <p><b>Note:</b> the values of the metrics are undefined in case of overflow (though it is
   * guaranteed not to throw an exception). If you require specific handling, we recommend
   * implementing your own stats collector.
   */
  public long requestCount() {

Pero el ejemplo aquí usa `PATCH` porque fue creado para estos casos de uso.

///

/// note | Nota

Observa que el modelo de entrada sigue siendo validado.

Entonces, si deseas recibir actualizaciones parciales que puedan omitir todos los atributos, necesitas tener un modelo con todos los atributos marcados como opcionales (con valores por defecto o `None`).

///

/// note | Hinweis

Beachten Sie, dass das hereinkommende Modell immer noch validiert wird.

Wenn Sie also Teil-Aktualisierungen empfangen wollen, die alle Attribute auslassen können, müssen Sie ein Modell haben, dessen Attribute alle als optional gekennzeichnet sind (mit Defaultwerten oder `None`).

   * href="http://tools.ietf.org/html/rfc4291#section-2.5.5.1">RFC 4291</a>.
   *
   * <p>NOTE: This method is different from {@link Inet6Address#isIPv4CompatibleAddress} in that it
   * more correctly classifies {@code "::"} and {@code "::1"} as proper IPv6 addresses (which they
   * are), NOT IPv4 compatible addresses (which they are generally NOT considered to be).
   *

   * method, {@code NaN} is treated as greater than all other values, and {@code 0.0 > -0.0}.
   *
   * <p><b>Note:</b> this method simply delegates to the JDK method {@link Double#compare}. It is
   * provided for consistency with the other primitive types, whose compare methods were not added
   * to the JDK until JDK 7.
   *
   * @param a the first {@code double} to compare
   * @param b the second {@code double} to compare