* character encoding. UTF-8 is defined in section D92 of <a
 * href="http://www.unicode.org/versions/Unicode6.2.0/ch03.pdf">The Unicode Standard Core
 * Specification, Chapter 3</a>.
 *
 * <p>The variant of UTF-8 implemented by this class is the restricted definition of UTF-8
 * introduced in Unicode 3.1. One implication of this is that it rejects <a
 * href="http://www.unicode.org/versions/corrigendum1.html">"non-shortest form"</a> byte sequences,

/**
 * Tests our AtomicHelper fallback strategies in AbstractFuture.
 *
 * <p>On different platforms AbstractFuture uses different strategies for its core synchronization
 * primitives. The strategies are all implemented as subtypes of AtomicHelper and the strategy is
 * selected in the static initializer of AbstractFuture. This is convenient and performant but
 * introduces some testing difficulties. This test exercises the fallback strategies.
 *

   * @throws UnsupportedOperationException if backward conversion is not implemented; this should be
   *     very rare. Note that if backward conversion is not only unimplemented but
   *     unimplement<i>able</i> (for example, consider a {@code Converter<Chicken, ChickenNugget>}),
   *     then this is not logically a {@code Converter} at all, and should just implement {@link
   *     Function}.
   */
  @ForOverride

 *     .makeMap();
 * }
 *
 * <p>These features are all optional; {@code new MapMaker().makeMap()} returns a valid concurrent
 * map that behaves similarly to a {@link ConcurrentHashMap}.
 *
 * <p>The returned map is implemented as a hash table with similar performance characteristics to
 * {@link ConcurrentHashMap}. It supports all optional operations of the {@code ConcurrentMap}
 * interface. It does not permit null keys or values.
 *

final class Murmur3_128HashFunction extends AbstractHashFunction implements Serializable {
  static final HashFunction MURMUR3_128 = new Murmur3_128HashFunction(0);

  static final HashFunction GOOD_FAST_HASH_128 =
      new Murmur3_128HashFunction(Hashing.GOOD_FAST_HASH_SEED);

  // TODO(user): when the shortcuts are implemented, update BloomFilterStrategies
  private final int seed;

 *
 * <h4 id="java8">Java 8+ equivalents</h4>
 *
 * If you are using Java version 8 or greater, you should generally use the static methods in {@link
 * Comparator} instead of {@code ComparisonChain}. The example above can be implemented like this:
 *
 * {@snippet :
 * import static java.util.Comparator.comparing;
 * import static java.util.Comparator.nullsLast;
 * import static java.util.Comparator.naturalOrder;
 *
 * ...

* The frontend (running in the user's browser) sends that `username` and `password` to a specific URL in our API (declared with `tokenUrl="token"`).
* The API checks that `username` and `password`, and responds with a "token" (we haven't implemented any of this yet).
    * A "token" is just a string with some content that we can use later to verify this user.
    * Normally, a token is set to expire after some time.

 * multiple variants of ASN.1, including:
 *
 *  * DER: Distinguished Encoding Rules. This further constrains ASN.1 for deterministic encoding.
 *  * BER: Basic Encoding Rules.
 *
 * This class was implemented according to the [X.690 spec][[x690]], and under the advice of
 * [Lets Encrypt's ASN.1 and DER][asn1_and_der] guide.
 *
 * [x690]: https://www.itu.int/rec/T-REC-X.690

        return if (delta > 0L) delta else 0L
      }

      if (lastModified != null && cacheResponse.request.url.query == null) {
        // As recommended by the HTTP RFC and implemented in Firefox, the max age of a document
        // should be defaulted to 10% of the document's age at the time it was served. Default
        // expiration dates aren't used for URIs containing a query.

Specific security vs. connectivity decisions are implemented by [ConnectionSpec](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/). OkHttp includes four built-in connection specs: