而我們使用這個模型同時宣告輸入與輸出：

{* ../../docs_src/response_model/tutorial002_py310.py hl[16] *}

現在，當瀏覽器建立一個帶有密碼的使用者時，API 會在回應中回傳相同的密碼。

在這個例子中可能不是問題，因為是同一個使用者送出該密碼。

但如果我們對其他「路徑操作」使用相同的模型，我們可能會把使用者密碼送給所有用戶端。

/// danger | 警告

除非你非常清楚所有影響並確定自己在做什麼，否則永遠不要儲存使用者的明文密碼，也不要像這樣在回應中傳送。

///

## 新增一個輸出模型 { #add-an-output-model }

我們可以改為建立一個包含明文密碼的輸入模型，以及一個不含密碼的輸出模型：

    }

    /*
     * TODO(cpovirk): Consider making this implementation closer to the mainline implementation.
     * (The difference was introduced as part of Java-8-specific changes in cl/132882204, but we
     * could probably make *some* of those changes here in the backport, too.)
     */
    public LoadingValueReference(ValueReference<K, V> oldValue) {
      this.oldValue = oldValue;
    }

    @Override

 *
 * <h2>Prefer <a href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a> over Guava's caching
 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a
 * nearly drop-in replacement. Note that it is not available for Android or GWT/J2CL and that it may
 * have <a href="https://github.com/ben-manes/caffeine/wiki/Guava">different (usually better)

 │  fastapi run                                        │
 │                                                     │
 ╰─────────────────────────────────────────────────────╯

INFO:     Will watch for changes in these directories: ['/home/user/code/awesomeapp']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles

 │  fastapi run                                        │
 │                                                     │
 ╰─────────────────────────────────────────────────────╯

INFO:     Will watch for changes in these directories: ['/home/user/code/awesomeapp']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles

// Adds a copy of function `func` and optionally its gradient function `grad`
// to `g`. Once `func`/`grad` is added to `g`, it can be called by creating
// an operation using the function's name.
// Any changes to `func`/`grad` (including deleting it) done after this method
// returns, won't affect the copy of `func`/`grad` in `g`.
// If `func` or `grad` are already in `g`, TF_GraphCopyFunction has no

func (sys *IAMSys) periodicRoutines(ctx context.Context, baseInterval time.Duration) {
	// Watch for IAM config changes for iamStorageWatcher.
	watcher, isWatcher := sys.store.IAMStorageAPI.(iamStorageWatcher)
	if isWatcher {
		go func() {
			ch := watcher.watch(ctx, iamConfigPrefix)
			for event := range ch {
				if err := sys.loadWatchedEvent(ctx, event); err != nil {
					// we simply log errors

     * to resolve SIDs using a cache and cache the results of any SIDs that
     * required resolving with the authority. SID cache entries are currently not
     * expired because under normal circumstances SID information never changes.
     *

 │  fastapi run                                        │
 │                                                     │
 ╰─────────────────────────────────────────────────────╯

INFO:     Will watch for changes in these directories: ['/home/user/code/awesomeapp']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles

    }
    return wrapCollection(key, collection);
  }

  /**
   * Generates a decorated collection that remains consistent with the values in the multimap for
   * the provided key. Changes to the multimap may alter the returned collection, and vice versa.
   */
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedCollection(key, collection, null);
  }