// JoinLoaders - joins multiple loaders into a single loader. The returned
// loader will call each of the given loaders in order. If any of the loaders
// return an error, the returned loader will return that error.
func JoinLoaders(loaders ...MetricsLoaderFn) MetricsLoaderFn {
	return func(ctx context.Context, m MetricValues, c *metricsCache) error {
		for _, loader := range loaders {
			if err := loader(ctx, m, c); err != nil {

   *     used as a {@code Function} only with cache loaders that throw only unchecked exceptions.)
   */
  @Deprecated
  @Override
  V apply(K key);

  /**
   * Loads a new value for {@code key}, possibly asynchronously. While the new value is loading the
   * previous value (if any) will continue to be returned by {@code get(key)} unless it is evicted.

   *
   * If the library is loaded in an application class loader, we try to break the cycle by loading
   * Finalizer in its own independent class loader:
   *
   * System class loader -> Application class loader -> ReferenceMap -> FinalizableReferenceQueue ->
   * etc. -> Decoupled class loader -> Finalizer
   *

   * {@linkplain Thread#getContextClassLoader() context class loader}. In simple environments, the
   * context class loader will find resources from the class path. In environments where different
   * threads can have different class loaders, for example app servers, the context class loader
   * will typically have been set to an appropriate loader for the current thread.
   *

 *
 * <p>This class can't depend on other Guava code. If we were to load this class in the same class
 * loader as the rest of Guava, this thread would keep an indirect strong reference to the class
 * loader and prevent it from being garbage collected. This poses a problem for environments where

	}

	// Loads things in the same order as `LoadIAMCache()`

	bootstrapTraceMsgFirstTime("loading policy documents")

	policyLoadStartTime := UTCNow()
	policiesList := listedConfigItems[policiesListKey]
	count := 32 // number of parallel IAM loaders
	for {
		if len(policiesList) < count {

  fun newBuilder(): Builder = commonNewBuilder()

  /**
   * Returns true if `other` is a `Headers` object with the same headers, with the same casing, in
   * the same order. Note that two headers instances may be *semantically* equal but not equal
   * according to this method. In particular, none of the following sets of headers are equal
   * according to this method:
   *
   * 1. Original
   * ```

	AmzMetaUnencryptedContentLength = "X-Amz-Meta-X-Amz-Unencrypted-Content-Length"
	AmzMetaUnencryptedContentMD5    = "X-Amz-Meta-X-Amz-Unencrypted-Content-Md5"

	// AWS server-side encryption headers for SSE-S3, SSE-KMS and SSE-C.
	AmzServerSideEncryption                      = "X-Amz-Server-Side-Encryption"
	AmzServerSideEncryptionKmsID                 = AmzServerSideEncryption + "-Aws-Kms-Key-Id"

And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

///

## Custom Headers

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

Y como la `Response` puede ser usada frecuentemente para configurar headers y cookies, **FastAPI** también la provee en `fastapi.Response`.

///

## Headers Personalizados

Ten en cuenta que se pueden añadir headers propietarios personalizados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando el prefijo 'X-'</a>.