private final boolean allowNulls;

  // Package-private so that it can be extended.
  MinimalCollection(Class<? super @NonNull E> type, boolean allowNulls, E... contents) {
    // TODO: consider making it shuffle the contents to test iteration order.
    this.contents = Platform.clone(contents);
    this.type = type;
    this.allowNulls = allowNulls;

    if (!allowNulls) {
      for (Object element : contents) {

 * <i>other type</i> of supplier is expected, use the method reference {@code supplier::get}. A
 * future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible

By default, **FastAPI** will create a `server` in the OpenAPI schema with the URL for the `root_path`.

But you can also provide other alternative `servers`, for example if you want *the same* docs UI to interact with both a staging and a production environment.

If you pass a custom list of `servers` and there's a `root_path` (because your API lives behind a proxy), **FastAPI** will insert a "server" with this `root_path` at the beginning of the list.

        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();
        // TODO(lowasser): consider making the entries live views
        return new AbstractIterator<Entry<E>>() {
          @Override
          protected @Nullable Entry<E> computeNext() {
            if (iterator1.hasNext()) {

        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();
        // TODO(lowasser): consider making the entries live views
        return new AbstractIterator<Entry<E>>() {
          @Override
          protected @Nullable Entry<E> computeNext() {
            if (iterator1.hasNext()) {

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        <img class="sponsor-image" src="/img/sponsors/coderabbit-banner.png" />
      </a>
    </div>
    <div class="item">
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 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V>
    implements ListenableFuture<V> {
  // TODO(cpovirk): explore ways of making ListenableFutureTask final. There are some valid reasons
  // such as BoundedQueueExecutorService to allow extends but it would be nice to make it final to
  // avoid unintended usage.

// `.TnitOnce`.
func New[T any]() *Cache[T] {
	return &Cache[T]{}
}

// NewFromFunc allocates a new cached value instance and initializes it with an
// update function, making it ready for use.
func NewFromFunc[T any](ttl time.Duration, opts Opts, update func(ctx context.Context) (T, error)) *Cache[T] {
	return &Cache[T]{
		ttl:      ttl,
		updateFn: update,
		opts:     opts,
	}
}

Mas você também pode fornecer outros `servers` alternativos, por exemplo, se quiser que a mesma interface de documentação interaja com ambientes de staging e produção.

Se você passar uma lista personalizada de `servers` e houver um `root_path` (porque sua API está atrás de um proxy), o **FastAPI** inserirá um "server" com esse `root_path` no início da lista.

Por exemplo:

## 附加的服务器

/// warning | 警告

此用例较难，可以跳过。

///

默认情况下，**FastAPI** 使用 `root_path` 的链接在 OpenAPI 概图中创建 `server`。

但也可以使用其它备选 `servers`，例如，需要同一个 API 文档与 staging 和生产环境交互。

如果传递自定义 `servers` 列表，并有 `root_path`（ 因为 API 使用了代理），**FastAPI** 会在列表开头使用这个 `root_path` 插入**服务器**。

例如：

{* ../../docs_src/behind_a_proxy/tutorial003.py hl[4:7] *}

这段代码生产如下 OpenAPI 概图：