* closed.
   *
   * <p>Usage guidelines for this method:
   *
   * <ul>
   *   <li>Use this method only when calling an API that returns a {@link ListenableFuture} or a
   *       {@code ClosingFuture}. If possible, prefer calling {@link #transform(ClosingFunction,
   *       Executor)} instead, with a function that returns the next value directly.
   *   <li>Call {@link DeferredCloser#eventuallyClose(Object, Executor) closer.eventuallyClose()}

  // 18,304
  private static final long EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT =
      // Both bytes are one byte characters
      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 2)
          +
          // The possible number of two byte characters
          TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS;

  // 2048
  private static final long THREE_BYTE_SURROGATES = 2 * 1024;

  // 61,440 [chars 0x0800 to 0xFFFF, minus surrogates]

 * body.
 *
 * ### The response body can be consumed only once.
 *
 * This class may be used to stream very large responses. For example, it is possible to use this
 * class to read a response that is larger than the entire memory allocated to the current process.
 * It can even stream a response larger than the total storage on the current device, which is a

   * processing and may run concurrently, for example, if the JVM flag {@code
   * -XX:+ExplicitGCInvokesConcurrent} is used.
   *
   * <p>Whenever possible, it is preferable to test directly for some observable change resulting
   * from GC, as with {@link #awaitClear}. Because there are no guarantees for the order of GC

    putEdge(3, 1);
  }

  // Element Mutation

  @Test
  public void putEdge_existingNodes() {
    assume().that(graphIsMutable()).isTrue();

    // Adding nodes initially for safety (insulating from possible future
    // modifications to proxy methods)
    addNode(N1);
    addNode(N2);

    assertThat(graphAsMutableGraph.putEdge(N1, N2)).isTrue();
  }

  @Test

        .supportsTlsExtensions(true)
        .build()

    /**
     * A backwards-compatible fallback configuration that works on obsolete client platforms and can
     * connect to obsolete servers. When possible, prefer to upgrade your client platform or server
     * rather than using this configuration.
     */
    @JvmField
    val COMPATIBLE_TLS =
      Builder(true)

   * processing and may run concurrently, for example, if the JVM flag {@code
   * -XX:+ExplicitGCInvokesConcurrent} is used.
   *
   * <p>Whenever possible, it is preferable to test directly for some observable change resulting
   * from GC, as with {@link #awaitClear}. Because there are no guarantees for the order of GC

# Démarrage

Le fichier **FastAPI** le plus simple possible pourrait ressembler à cela  :

{* ../../docs_src/first_steps/tutorial001.py *}

Copiez ce code dans un fichier nommé `main.py`.

Démarrez le serveur :

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

## **FastAPI** plug-ins { #fastapi-plug-ins }

Integrations and "plug-ins" can be built using the **Dependency Injection** system. But in fact, there is actually **no need to create "plug-ins"**, as by using dependencies it's possible to declare an infinite number of integrations and interactions that become available to your *path operation functions*.

The first one will always be used since the path matches first.

## Predefined values { #predefined-values }

If you have a *path operation* that receives a *path parameter*, but you want the possible valid *path parameter* values to be predefined, you can use a standard Python <abbr title="Enumeration">`Enum`</abbr>.

### Create an `Enum` class { #create-an-enum-class }