* identical inputs: This sounds like it ought to be a problem here, since the goals of this class
   * include testing that {@code equals()} is reflexive and is tolerant of {@code null}. However,
   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.
   */
  private final Equivalence<? super T> equivalence;

   * would be the right tool for the job here: {@code @Nullable} is the annotation that we're trying
   * to get rid of, and {@code @NonNull} would be wrong for our use case for the same reason as
   * {@code requireNonNull}: Our use case is the one in which {@code T} has parametric nullness—and
   * thus its value may be legitimately {@code null}.)
   */
  @SuppressWarnings("nullness")
  @ParametricNullness

* `Optional`
* ...등등

위와 같은 타입은 **Generic(제네릭) 타입** 혹은 **Generics(제네릭스)**라고 불립니다.

### 타입으로서의 클래스

변수의 타입으로 클래스를 선언할 수도 있습니다.

이름(name)을 가진 `Person` 클래스가 있다고 해봅시다.

{* ../../docs_src/python_types/tutorial010.py hl[1:3] *}


그렇게 하면 변수를 `Person`이라고 선언할 수 있게 됩니다.

{* ../../docs_src/python_types/tutorial010.py hl[6] *}


그리고 역시나 모든 에디터 도움을 받게 되겠죠.

<img src="/img/python-types/image06.png">

Dan krijg je ook nog eens volledige editorondersteuning:

<img src="/img/python-types/image06.png">

Merk op dat dit betekent dat "`one_person` een **instantie** is van de klasse `Person`".

Dit betekent niet dat `one_person` de **klasse** is met de naam `Person`.

## Pydantic modellen

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> is een Python-pakket voor het uitvoeren van datavalidatie.

  }

  // Wrapper of EnumMultiset factory methods, because we need to skip create(Class).
  // create(Enum1.class) is equal to create(Enum2.class) but testEquals() expects otherwise.
  // For the same reason, we need to skip create(Iterable, Class).
  private static class EnumMultisetFactory {
    @Keep // used reflectively by testEquals
    public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {

////

### 🎓 🆎

👆 💪 📣 🎓 🆎 🔢.

➡️ 💬 👆 ✔️ 🎓 `Person`, ⏮️ 📛:

```Python hl_lines="1-3"
{!../../docs_src/python_types/tutorial010.py!}
```

⤴️ 👆 💪 📣 🔢 🆎 `Person`:

```Python hl_lines="6"
{!../../docs_src/python_types/tutorial010.py!}
```

& ⤴️, 🔄, 👆 🤚 🌐 👨‍🎨 🐕‍🦺:

             * necessarily populated with header data because they're not writing
             * the header, only their body. But for whatever reason one might wish
             * to populate fields if the writeXxx operation needs this header data
             * for whatever reason. I copy over the uid here so it appears correct
             * in logging output. Logging of andx segments of messages inadvertantly

/**
 * A container for data that is specific to a session.
 * All components may use this storage to associate arbitrary data with a session.
 * <p>
 * Unlike a cache, this session data is not subject to purging. For this same reason, session data should also not be
 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *

  internal val writeTimeout = StreamTimeout()

  /**
   * The reason why this stream was closed, or null if it closed normally or has not yet been
   * closed.
   *
   * If there are multiple reasons to abnormally close this stream (such as both peers closing it
   * near-simultaneously) then this is the first reason known to this peer.
   */
  internal var errorCode: ErrorCode? = null
    get() = withLock { field }

A single HTTP call may require follow-up requests to be made to handle authentication challenges, redirects, and HTTP-layer timeouts. In such cases multiple connections, requests, and responses may be attempted. Follow-ups are another reason a single call may trigger multiple events of the same type.

![Events Diagram](../assets/images/******@****.***)

### Availability