// creation cost.
  @CanIgnoreReturnValue
  static Object checkElementNotNull(@CheckForNull Object element, int index) {
    if (element == null) {
      throw new NullPointerException("at index " + index);
    }
    return element;
  }

```YAML hl_lines="8"
site_name: FastAPI
# More stuff
nav:
- FastAPI: index.md
- Languages:
  - en: /
  - es: /es/
- features.md
```

* 📂 ⬜ 📁 📁 🇪🇸 👆 ✍, ✅:

```
docs/es/mkdocs.yml
```

* 🚮 ⚫️ 📤 ☑ 🎏 🗺 ⚫️ 🇪🇸, ✅:

```YAML hl_lines="8"
site_name: FastAPI
# More stuff
nav:
- FastAPI: index.md
- Languages:
  - en: /
  - es: /es/
- features.md
```

            String prefix2,
            ModelBuildingRequest request) {
        Severity errOn31 = getSeverity(request, ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_3_1);

        Map<String, Plugin> index = new HashMap<>();

        for (Plugin plugin : plugins) {
            if (plugin.getGroupId() == null
                    || (plugin.getGroupId() != null

		}
		num = int16(amount)
	} else if p.peek() == '[' {
		// parses an element: [Index]
		p.get('[')
		tok := p.get(scanner.Int)
		index, err := strconv.ParseInt(tok.String(), 10, 16)
		p.get(']')
		if err != nil {
			p.errorf("parsing element index: %s", err)
		}
		isIndex = true
		isAmount = false
		num = int16(index)
	}

	switch p.arch.Family {
	case sys.ARM64:

    //                                                                      Search Execute
    //                                                                      ==============
    @Execute
    public HtmlResponse index() {
        if (isLoginRequired()) {
            return redirectToLogin();
        }

        return asHtml(virtualHost(path_IndexJsp)).useForm(SearchForm.class, op -> {
            op.setup(form -> {

    //                                                                      Search Execute
    //                                                                      ==============

    @Execute
    public HtmlResponse index() {
        if (isLoginRequired()) {
            return redirectToLogin();
        }

        return asHtml(virtualHost(path_HelpJsp)).useForm(SearchForm.class, op -> {
            op.setup(form -> {

 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonMatcher {
  public abstract boolean matches();

  public abstract boolean find();

  public abstract boolean find(int index);

  public abstract String replaceAll(String replacement);

  public abstract int end();

  public abstract int start();

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### 他のAPIドキュメント

次に、<a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>にアクセスします。

先ほどとは異なる、自動生成された対話的APIドキュメントが表示されます (<a href="https://github.com/Rebilly/ReDoc" class="external-link" target="_blank">ReDoc</a>によって提供):

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

### OpenAPI

  }

  private static class DontStringMeBro implements CharSequence {
    @Override
    public int length() {
      return 3;
    }

    @Override
    public char charAt(int index) {
      return "foo".charAt(index);
    }

    @Override
    public CharSequence subSequence(int start, int end) {
      return "foo".subSequence(start, end);
    }

    @Override
    public String toString() {

///

**FastAPI** целиком основан на Pydantic.

Вы увидите намного больше всего этого на практике в [Руководстве пользователя](tutorial/index.md){.internal-link target=_blank}.

## Аннотации типов в **FastAPI**

**FastAPI** получает преимущества аннотаций типов для выполнения определённых задач.