///

## Type Hints met Metadata Annotaties

Python heeft ook een functie waarmee je **extra <abbr title="Data over de data, in dit geval informatie over het type, bijvoorbeeld een beschrijving.">metadata</abbr>** in deze type hints kunt toevoegen met behulp van `Annotated`.

//// tab | Python 3.9+

In Python 3.9 is `Annotated` onderdeel van de standaardpakket, dus je kunt het importeren vanuit `typing`.

### Getest

* 100% <abbr title="De hoeveelheid code die automatisch wordt getest">van de code is getest</abbr>.
* 100% <abbr title="Python type annotaties, hiermee kunnen je editor en externe tools je beter ondersteunen">type geannoteerde</abbr> codebase.
* Wordt gebruikt in productietoepassingen.

## Starlette functies

          <option value="io.reactivex.annotations.Beta" />
          <option value="io.reactivex.annotations.Experimental" />
          <option value="org.apache.http.annotation.Beta" />
          <option value="org.gradle.api.Incubating" />
          <option value="org.jetbrains.annotations.ApiStatus.Experimental" />
          <option value="rx.annotations.Beta" />
          <option value="rx.annotations.Experimental" />
        </set>

And tools will also be happy because both `RedirectResponse` and `JSONResponse` are subclasses of `Response`, so the type annotation is correct.

### Annotate a Response Subclass { #annotate-a-response-subclass }

You can also use a subclass of `Response` in the type annotation:

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.8+

```Python
q: Annotated[Union[str, None]] = None
```

////

Обе эти версии означают одно и тоже. `q` - это параметр, который может быть `str` или `None`, и по умолчанию он будет принимать `None`.

Давайте повеселимся. 🎉

## Добавим `Query` в `Annotated` для query-параметра `q`

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

  }

  /**
   * Find all the tester annotations declared on a tester class or method.
   *
   * @param classOrMethod a class or method whose tester annotations to find
   * @return an iterable sequence of tester annotations on the class
   */
  public static Iterable<Annotation> getTesterAnnotations(AnnotatedElement classOrMethod) {
    synchronized (annotationCache) {
      List<Annotation> annotations = annotationCache.get(classOrMethod);

  }

  /**
   * Find all the tester annotations declared on a tester class or method.
   *
   * @param classOrMethod a class or method whose tester annotations to find
   * @return an iterable sequence of tester annotations on the class
   */
  public static Iterable<Annotation> getTesterAnnotations(AnnotatedElement classOrMethod) {
    synchronized (annotationCache) {
      List<Annotation> annotations = annotationCache.get(classOrMethod);

If we had declared `-> HeroPublic`, your editor and linter would complain (rightfully so) that you are returning a `Hero` instead of a `HeroPublic`.

By declaring it in `response_model` we are telling **FastAPI** to do its thing, without interfering with the type annotations and the help from your editor and other tools.