// updateFn must return an updated value.
	// If an error is returned the cached value is not set.
	// Only one caller will call this function at any time, others will be blocking.
	// The returned value can no longer be modified once returned.
	// Should be set before calling Get().
	updateFn func(ctx context.Context) (T, error)

	// ttl for a cached value.
	ttl time.Duration

	opts Opts

	if err != nil {
		return key, err
	}
	return unsealObjectKey(clientKey[:], metadata, bucket, object)
}

// CreateMetadata encodes the sealed key into the metadata
// and returns the modified metadata. It allocates a new
// metadata map if metadata is nil.
func (ssec) CreateMetadata(metadata map[string]string, sealedKey SealedKey) map[string]string {
	if sealedKey.Algorithm != SealAlgorithm {

Some requests will have a cached response. When this cached response isn’t fresh, OkHttp can do a _conditional GET_ to download an updated response if it’s newer than what’s cached. This requires headers like `If-Modified-Since` and `If-None-Match` to be added.

## Rewriting Responses

* **`300 - 399`** stehen für „Redirection“ („Umleitung“). Responses mit diesen Statuscodes können einen Body haben oder nicht, außer bei `304`, „Not Modified“ („Nicht verändert“), die keinen haben darf.
* **`400 - 499`** stehen für „Client error“-Responses („Client-Fehler“). Diese sind die zweithäufigsten, die Sie vermutlich verwenden werden.

* **`300 - 399`** – статус-коды, сообщающие о перенаправлениях. Ответы с этими кодами статуса могут иметь или не иметь тело, за исключением ответов со статусом `304`, "Not Modified", у которых не должно быть тела.
* **`400 - 499`** – статус-коды, сообщающие о клиентской ошибке. Это ещё одна наиболее часто используемая категория.
    * Пример – код `404` для статуса "Not Found".

import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Set;

      } catch (NullPointerException | ClassCastException e) {
        return 0;
      }
    }

    /**
     * {@inheritDoc}
     *
     * <p>If the data in the multiset is modified by any other threads during this method, it is
     * undefined which (if any) of these modifications will be reflected in the result.
     */
    @Override
    public int size() {
      long sum = 0L;

Cela a été modifié dans la version 0.110.0 pour corriger une consommation de mémoire non gérée due aux exceptions transmises sans gestionnaire (erreurs internes du serveur), et pour rendre le comportement cohérent avec celui du code Python classique.

    /**
     * Set the last modified time of the file. The time is specified as milliseconds
     * from Jan 1, 1970 which is the same as that which is returned by the
     * <code>lastModified()</code> method.
     * <br>
     * This method does not apply to workgroups, servers, or shares.
     *
     * @param time
     *            the last modified time as milliseconds since Jan 1, 1970

    assertWithMessage("null escaper should have no effect").that(escaper.escape(s)).isEqualTo(s);
  }

  public void testBuilderInitialStateNoReplacement() {
    // Unsafe characters aren't modified by default (unsafeReplacement == null).
    Escaper escaper = Escapers.builder().setSafeRange('a', 'z').build();
    assertThat(escaper.escape("The Quick Brown Fox")).isEqualTo("The Quick Brown Fox");
  }