*     used as a {@code Function} only with cache loaders that throw only unchecked exceptions.)
   */
  @Deprecated
  @Override
  V apply(K key);

  /**
   * Loads a new value for {@code key}, possibly asynchronously. While the new value is loading the
   * previous value (if any) will continue to be returned by {@code get(key)} unless it is evicted.

It could be just one or two lines of code, like:

```Python
callback_url = "https://example.com/api/v1/invoices/events/"
httpx.post(callback_url, json={"description": "Invoice paid", "paid": True})
```

But possibly the most important part of the callback is making sure that your API user (the external developer) implements the *external API* correctly, according to the data that *your API* is going to send in the request body of the callback, etc.

            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

          @Override
          String toPendingString() {
            return "";
          }

            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

          @Override
          String toPendingString() {
            return "";
          }

        fi
        # Roll the args list around exactly as many times as the number of
        # args, so each arg winds up back in the position where it started, but
        # possibly modified.
        #
        # NB: a `for` loop captures its iteration list before it begins, so
        # changing the positional parameters here affects neither the number of

# Stream de JSON Lines { #stream-json-lines }

Você pode ter uma sequência de dados que deseja enviar em um "**Stream**"; é possível fazer isso com **JSON Lines**.

/// info | Informação

Adicionado no FastAPI 0.134.0.

///

## O que é um Stream? { #what-is-a-stream }

"**Streaming**" de dados significa que sua aplicação começará a enviar itens ao cliente sem esperar que toda a sequência esteja pronta.

    return GetCheckedTypeValidatorHolder.WeakSetValidator.INSTANCE;
  }

  /**
   * Provides a check of whether an exception type is valid for use with {@link
   * FuturesGetChecked#getChecked(Future, Class)}, possibly using caching.
   *
   * <p>Uses reflection to gracefully fall back to when certain implementations aren't available.
   */
  private static final class GetCheckedTypeValidatorHolder {

Pero es posible personalizarlo, puedes establecer un CDN específico, o servir los archivos tú mismo.

## CDN Personalizado para JavaScript y CSS { #custom-cdn-for-javascript-and-css }

Las integraciones y "plug-ins" pueden construirse usando el sistema de **Inyección de Dependencias**. Pero, de hecho, en realidad **no hay necesidad de crear "plug-ins"**, ya que al usar dependencias es posible declarar una cantidad infinita de integraciones e interacciones que se vuelven disponibles para tus *path operation functions*.

Para conseguir isso, o backend `:80` deve ter uma lista de "origens permitidas".

Neste caso, a lista terá que incluir `http://localhost:8080` para o frontend `:8080` funcionar corretamente.

## Curingas { #wildcards }

É possível declarar a lista como `"*"` (um "curinga") para dizer que tudo está permitido.