But `open()` doesn't use `async` and `await`.

So, we declare the event handler function with standard `def` instead of `async def`.

///

### `startup` and `shutdown` together

There's a high chance that the logic for your *startup* and *shutdown* is connected, you might want to start something and then finish it, acquire a resource and then release it, etc.

   * Returns {@code x}, rounded to a {@code double} with the specified rounding mode. If {@code x}
   * is precisely representable as a {@code double}, its {@code double} value will be returned;
   * otherwise, the rounding will choose between the two nearest representable values with {@code
   * mode}.
   *
   * <p>For the case of {@link RoundingMode#HALF_DOWN}, {@code HALF_UP}, and {@code HALF_EVEN},

,"bosnia and herzegovina","botswana","bouvet island","brazil","british indian ocean territory","brunei darussalam","bulgaria","burkina faso","burundi","cabo verde","cambodia","cameroon","canada","cayman islands","central african republic","chad","chile","china","christmas island","cocos islands","colombia","comoros","democratic republic of the congo","congo","cook islands","costa rica","côte d'ivoire","croatia","cuba","curaçao","cyprus","czechia","denmark","djibouti","dominica","dominican republ...

       *
       * 1. On Android, querying a WeakReference blocks if the GC is doing an otherwise-concurrent
       * pass.
       *
       * 2. We would probably choose to compare exceptions using == instead of equals() (for
       * consistency with how weak references are cleared). That's a behavior change -- arguably the
       * removal of a feature.
       *

「Releases only」ではなく「Watching」を選択すると、新たなissueが立てられた際に通知されます。

そして、issueを解決し他の人を助けることができます。

## issuesを立てる

GitHubレポジトリで<a href="https://github.com/fastapi/fastapi/issues/new/choose" class="external-link" target="_blank">新たなissueを立てられます</a>。例えば:

* 質問、または、問題の報告
* 新機能の提案

**Note**: issueを立てた人は、他の人の手助けもお願いします。😉

## プルリクエストをする

   *
   * @param method defaults to "GET" if [body] is null, and "POST" otherwise.
   */
  constructor(
    url: HttpUrl,
    headers: Headers = headersOf(),
    // '\u0000' is a sentinel value that'll choose based on what the body is:
    method: String = "\u0000",
    body: RequestBody? = null,
  ) : this(
    Builder()
      .url(url)
      .headers(headers)
      .method(
        when {

import javax.annotation.CheckForNull;

/**
 * A set comprising zero or more {@linkplain Range#isEmpty nonempty}, {@linkplain
 * Range#isConnected(Range) disconnected} ranges of type {@code C}.
 *
 * <p>Implementations that choose to support the {@link #add(Range)} operation are required to
 * ignore empty ranges and coalesce connected ranges. For example:
 *
 * <pre>{@code
 * RangeSet<Integer> rangeSet = TreeRangeSet.create();

   * #newArrayListWithCapacity} (see that method for further advice on usage).
   *
   * <p><b>Note:</b> This method will soon be deprecated. Even in the rare case that you do want
   * some amount of padding, it's best if you choose your desired amount explicitly.
   *
   * @param estimatedSize an estimate of the eventual {@link List#size()} of the new list
   * @return a new, empty {@code ArrayList}, sized appropriately to hold the estimated number of

     * (if applicable). This process will essentially remove duplicate repositories by merging them into one equivalent
     * repository. It is worth to point out that merging does not simply choose one of the input repositories and
     * discards the others but actually combines their possibly different policies.
     *
     * @param repositories The original repositories, may be {@code null}.

Toutes les fonctionnalités qui s'appliquent aux paramètres de chemin s'appliquent aussi aux paramètres de requête :

* Support de l'éditeur : vérification d'erreurs, auto-complétion, etc.
* <abbr title="conversion de la chaîne de caractères venant de la requête HTTP en données Python">"Parsing"</abbr> de données.
* Validation de données.
* Annotations d'API et documentation automatique.

## Valeurs par défaut