This means:

* The variable `prices` is a `dict`:
    * The keys of this `dict` are of type `str` (let's say, the name of each item).
    * The values of this `dict` are of type `float` (let's say, the price of each item).

#### Union { #union }

You can declare that a variable can be any of **several types**, for example, an `int` or a `str`.

   */
  public List<Long> asList() {
    /*
     * Typically we cache this kind of thing, but much repeated use of this view is a performance
     * anti-pattern anyway. If we cache, then everyone pays a price in memory footprint even if
     * they never use this method.
     */
    return new AsList(this);
  }

  private static final class AsList extends AbstractList<Long>

   */
  public List<Integer> asList() {
    /*
     * Typically we cache this kind of thing, but much repeated use of this view is a performance
     * anti-pattern anyway. If we cache, then everyone pays a price in memory footprint even if
     * they never use this method.
     */
    return new AsList(this);
  }

  private static final class AsList extends AbstractList<Integer>

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

여러분이 이전에 불가능하다고 고려했던 코드도 완성할 수 있을 겁니다. 예를 들어, 요청에서 전달되는 (중첩될 수도 있는)JSON 본문 내부에 있는 `price` 키입니다.

잘못된 키 이름을 적을 일도, 문서를 왔다 갔다할 일도 없으며, 혹은 마지막으로 `username` 또는 `user_name`을 사용했는지 찾기 위해 위 아래로 스크롤할 일도 없습니다.

### 토막 정보

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

以前は不可能だと考えていたコードでさえ補完されます。例えば、リクエストからのJSONボディ（ネストされている可能性がある）内の `price`キーです。

間違ったキー名を入力したり、ドキュメント間を行き来したり、上下にスクロールして`username`と`user_name`のどちらを使用したか調べたりする必要はもうありません。

### 簡潔

すべてに適切な**デフォルト**があり、オプションの構成ができます。必要なことを実行し、必要なAPIを定義するためにすべてのパラメーターを調整できます。

ただし、デフォルトでもすべて **うまくいきます**。

 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashSet}.
 * Generally speaking, this class reduces object allocation and memory consumption at the price of
 * moderately increased constant factors of CPU. Only use this class when there is a specific reason
 * to prioritize memory over CPU.
 *
 * @author Dimitris Andreou
 * @author Jon Noack
 */

 * guarantees.
 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashMap}.
 * Generally speaking, this class reduces object allocation and memory consumption at the price of
 * moderately increased constant factors of CPU. Only use this class when there is a specific reason
 * to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 * @author Jon Noack
 */

Comme les paramètres sont décrits avec des types TypeScript (similaires aux type hints de Python), la prise en charge
par l'éditeur est assez bonne.

 * guarantees.
 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashMap}.
 * Generally speaking, this class reduces object allocation and memory consumption at the price of
 * moderately increased constant factors of CPU. Only use this class when there is a specific reason
 * to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 * @author Jon Noack
 */

non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.

  You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

  5. Conveying Modified Source Versions.

  You may convey a work based on the Program, or the modifications to