We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

All the data conversion, validation, documentation, etc. will still work as normally.

That way, we can declare just the differences between the models (with plaintext `password`, with `hashed_password` and without password):

  // TODO: IdentityHashMap, AbstractMap

  private static Map<String, String> toHashMap(Entry<String, String>[] entries) {
    return populate(new HashMap<String, String>(), entries);
  }

  // TODO: call conversion constructors or factory methods instead of using
  // populate() on an empty map
  private static <T, M extends Map<T, String>> M populate(M map, Entry<T, String>[] entries) {
    for (Entry<T, String> entry : entries) {

/// note

"Notez que, bien que nous ayons déclaré le paramètre `item` de la même manière que précédemment, il est maintenant associé à la clé `item` dans le corps de la requête."`.

///

**FastAPI** effectue la conversion de la requête de façon transparente, de sorte que les objets `item` et `user` se trouvent correctement définis.

      /*
       * For most values, the conversion from roundArbitrarily to roundArbitrarilyAsLong is
       * lossless. In that case we can compare x to roundArbitrarily using Long.compare(x,
       * roundArbitrarilyAsLong). The exception is for values where the conversion to double rounds
       * up to give roundArbitrarily equal to 2^63, so the conversion back to long overflows and

/// check

This will give you editor support inside of your function, with error checks, completion, etc.

///

## Data <abbr title="also known as: serialization, parsing, marshalling">conversion</abbr>

If you run this example and open your browser at <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a>, you will see a response of:

```JSON
{"item_id":3}

/// check | Revisa

Esto te dará soporte en el editor dentro de tu función, con chequeo de errores, auto-completado, etc.

///

## <abbr title="también conocido en inglés como: serialization, parsing, marshalling">Conversión</abbr> de datos

Si corres este ejemplo y abres tu navegador en <a href="http://127.0.0.1:8000/items/3" class="external-link" target="_blank">http://127.0.0.1:8000/items/3</a> verás una respuesta de:

```JSON
{"item_id":3}

* <abbr title="also known as: serialization, parsing, marshalling">Conversion</abbr> of input data: coming from the network to Python data and types. Reading from:
    * JSON.
    * Path parameters.
    * Query parameters.
    * Cookies.
    * Headers.
    * Forms.
    * Files.

Prefer to use the `Annotated` version if possible.

///

```Python
commons: CommonQueryParams ...
```

////

...doesn't have any special meaning for **FastAPI**. FastAPI won't use it for data conversion, validation, etc. (as it is using the `Depends(CommonQueryParams)` for that).

You could actually write just:

//// tab | Python 3.8+

```Python
commons: Annotated[Any, Depends(CommonQueryParams)]
```

func isASCII(s string) bool {
	for _, c := range s {
		if c >= 0x80 || c == 0x00 {
			return false
		}
	}
	return true
}

// toASCII converts the input to an ASCII C-style string.
// This is a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
	if isASCII(s) {
		return s
	}
	b := make([]byte, 0, len(s))
	for _, c := range s {
		if c < 0x80 && c != 0x00 {
			b = append(b, byte(c))

  // TODO: IdentityHashMap, AbstractMap

  private static Map<String, String> toHashMap(Entry<String, String>[] entries) {
    return populate(new HashMap<String, String>(), entries);
  }

  // TODO: call conversion constructors or factory methods instead of using
  // populate() on an empty map
  private static <T, M extends Map<T, String>> M populate(M map, Entry<T, String>[] entries) {
    for (Entry<T, String> entry : entries) {