//   into memory, any mutation on xl.meta subsequently is
		//   inconsequential to the overall read operation.
		// - xl.meta metadata is still verified for quorum under lock()
		//   however writing the response doesn't need to serialize
		//   concurrent writers
		unlockOnDefer = true
		nsUnlocker = func() { lock.RUnlock(lkctx) }
	}

 * bandwidth.
 *
 * The Cache instance must have exclusive access to the [directory], since the internal data structures
 * may cause corruption or runtime errors if not. It may however be shared amongst multiple OkHttpClient
 * instances.
 *
 * ## Cache Optimization
 *
 * To measure cache effectiveness, this class tracks three statistics:
 *

   */
  public static boolean hasCycle(Network<?, ?> network) {
    // In a directed graph, parallel edges cannot introduce a cycle in an acyclic graph.
    // However, in an undirected graph, any parallel edge induces a cycle in the graph.
    if (!network.isDirected()
        && network.allowsParallelEdges()
        && network.edges().size() > network.asGraph().edges().size()) {

    void tryClose() {
        synchronized (this.LOCK) {

            /*
             * Yes, there is the potential to drop packets
             * because we might close the socket during a
             * request. However the chances are slim and the
             * retry code should ensure the overall request
             * is serviced. The alternative complicates things
             * more than I think is worth it.
             */

   * order. They also specify the behavior of the {@code equals}, {@code hashCode}, and {@code
   * toString} methods for the multimap and its returned views. However, the multimap's {@code get}
   * method returns instances of a different class than {@code factory.get()} does.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the collections generated by

   * order. They also specify the behavior of the {@code equals}, {@code hashCode}, and {@code
   * toString} methods for the multimap and its returned views. However, the multimap's {@code get}
   * method returns instances of a different class than {@code factory.get()} does.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the collections generated by

    } catch (NoSuchMethodException shouldBeImpossible) {
      // Fine: If it doesn't exist, then there's no chance that we're going to be asked to test it.
    }

    /*
     * These methods "should" call checkNotNull. However, I'm wary of accidentally introducing
     * anything that might slow down execution on such a hot path. Given that the methods are only
     * package-private, I feel OK with just not testing them for NPE.
     *

    /*
     * Verify that it is not possible to instantiate an Inet6Address
     * from an "IPv4 mapped" IPv6 address.  Our String-based method can
     * at least identify them, however.
     */
    String mappedStr = "::ffff:192.168.0.1";
    assertTrue(InetAddresses.isMappedIPv4Address(mappedStr));
    InetAddress mapped = InetAddresses.forString(mappedStr);

   * to use {@code Predicates.<Object>in()}.
   *
   * <p>You may prefer to use a method reference (e.g., {@code target::contains}) instead of this
   * method. However, there are some subtle considerations:
   *
   * <ul>
   *   <li>The {@link Predicate} returned by this method is {@link Serializable}.

   * trace but faster iteration over parts of the trace. Here, "slower" and "faster" are defined in
   * comparison to the normal way to access the stack trace, {@link Throwable#getStackTrace()
   * throwable.getStackTrace()}. Note, however, that this method's special implementation is not
   * available for all platforms and configurations. If that implementation is unavailable, this