* all references {@code x}, {@code y}, and {@code z} (any of which may be null):
   *
   * <ul>
   *   <li>{@code equivalent(x, x)} is true (<i>reflexive</i> property)
   *   <li>{@code equivalent(x, y)} and {@code equivalent(y, x)} each return the same result
   *       (<i>symmetric</i> property)
   *   <li>If {@code equivalent(x, y)} and {@code equivalent(y, z)} are both true, then {@code

 *
 * <ul>
 *   <li>It looks only for files and JARs in URLs available from {@link URLClassLoader} instances or
 *       the {@linkplain ClassLoader#getSystemClassLoader() system class loader}. This means it does
 *       not look for classes in the <i>module path</i>.
 *   <li>It understands only {@code file:} URLs. This means that it does not understand <a

        final byte[] suffix = new byte[label.length + context.length + 5];
        // per bouncycastle
        // <li>1: K(i) := PRF( KI, [i]_2 || Label || 0x00 || Context || [L]_2 ) with the counter at the very beginning
        // of the fixedInputData (The default implementation has this format)</li>
        // with the parameters
        // <li>1. KDFCounterParameters(ki, null, "Label || 0x00 || Context || [L]_2]", 8);

 *
 * <p>Some uses of this class include
 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})

   * class documentation above). This method is <i>generally expected</i>, but not absolutely
   * required, to have the following properties:
   *
   * <ul>
   *   <li>Its execution does not cause any observable side effects.
   *   <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal
   *       Objects.equal}{@code (a, b)} implies that {@code predicate.apply(a) ==
   *       predicate.apply(b))}.

   *
   * <ol>
   *   <li>The state of the RateLimiter (storedPermits) is a vertical line in this figure.
   *   <li>When the RateLimiter is not used, this goes right (up to maxPermits)
   *   <li>When the RateLimiter is used, this goes left (down to zero), since if we have
   *       storedPermits, we serve from those first

 * instances:
 *
 * <ul>
 *   <li>If you receive them from an {@code java.util.concurrent.ExecutorService}, convert that
 *       service to a {@link ListeningExecutorService}, usually by calling {@link
 *       MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService)
 *       MoreExecutors.listeningDecorator}.
 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,

 *
 * <p>This pattern ensures the following:
 *
 * <ul>
 *   <li>Each {@code Closeable} resource that is successfully registered will be closed later.
 *   <li>If a {@code Throwable} is thrown in the try block, no exceptions that occur when attempting
 *       to close resources will be thrown from the finally block. The throwable from the try block
 *       will be thrown.

    // Field validation
    // ----------------------------------------------------------------------

    /**
     * Asserts:
     * <p/>
     * <ul>
     * <li><code>string.length != null</code>
     * <li><code>string.length > 0</code>
     * </ul>
     */
    private static boolean validateStringNotEmpty(

<style>
  main ul li { margin: 0.5em 0; }
</style>

## DRAFT RELEASE NOTES — Introduction to Go 1.27 {#introduction}

**Go 1.27 is not yet released. These are work-in-progress release notes.