*
     * @param session the {@link Session}, must not be {@code null}
     * @param node the {@link Node} to flatten, must not be {@code null}
     * @param scope an optional {@link PathScope} to filter out dependencies
     * @return the flattened list of node
     * @throws DependencyResolverException
     */

	list *LruList[K, V]

	// The LRU Key of this element.
	Key K

	// The Value stored with this element.
	Value V

	// The time this element would be cleaned up, optional
	ExpiresAt time.Time

	// The expiry bucket item was put in, optional
	ExpireBucket uint8
}

// PrevEntry returns the previous list element or nil.
func (e *Entry[K, V]) PrevEntry() *Entry[K, V] {

import java.util.Map;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and

Например, модель выше описывает такой JSON "объект" (или Python `dict`):

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...так как `description` и `tax` являются необязательными (со значением по умолчанию `None`), такой JSON "объект" тоже будет корректным:

```JSON
{

Это не является ограничением **FastAPI**, это часть протокола HTTP.

///

## Необязательная загрузка файлов { #optional-file-upload }

Вы можете сделать загрузку файла необязательной, используя стандартные аннотации типов и установив значение по умолчанию `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

 * existing key-value pair has no effect.
 *
 * <p>Null keys and values are permitted (provided, of course, that the respective comparators
 * support them). All optional multimap methods are supported, and all returned views are
 * modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent

Documentation = "https://fastapi.tiangolo.com/"
Repository = "https://github.com/fastapi/fastapi"
Issues = "https://github.com/fastapi/fastapi/issues"
Changelog = "https://fastapi.tiangolo.com/release-notes/"

[project.optional-dependencies]

standard = [
    "fastapi-cli[standard] >=0.0.8",
    # For the test client
    "httpx >=0.23.0,<1.0.0",
    # For templates
    "jinja2 >=3.1.5",
    # For forms and file uploads

 * Attempts to {@code put} an element into a full queue will result in the operation blocking;
 * attempts to {@code take} an element from an empty queue will similarly block.
 *
 * <p>This class supports an optional fairness policy for ordering waiting producer and consumer
 * threads. By default, this ordering is not guaranteed. However, a queue constructed with fairness

Isso não é uma limitação do **FastAPI**, é parte do protocolo HTTP.

///

## Upload de Arquivo Opcional { #optional-file-upload }

Você pode tornar um arquivo opcional usando anotações de tipo padrão e definindo um valor padrão de `None`:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

Por ejemplo, el modelo anterior declara un “`object`” JSON (o `dict` en Python) como:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...dado que `description` y `tax` son opcionales (con un valor por defecto de `None`), este “`object`” JSON también sería válido:

```JSON
{