*
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.
   *   <li>All methods that return objects that can indirectly mutate the collection throw
   *       UnsupportedOperationException when those mutators are called.
   * </ol>
   *
   * @param collection the presumed-immutable collection

     * Do not instantiate.
     */
    protected ClassLoaderUtil() {
    }

    /**
     * Returns the class loader.
     * <p>
     * The class loader is searched in the following order:
     * </p>
     * <ol>
     * <li>If the context class loader is set for the calling thread, that context class loader</li>
     * <li>If the class loader that loaded the target class can be obtained, that class loader</li>

/**
 * Implements the MD4 message digest algorithm in Java.
 * <p>
 * <b>References:</b>
 * <ol>
 *   <li> Ronald L. Rivest,
 *        "<a href="http://www.roxen.com/rfc/rfc1320.html">
 *        The MD4 Message-Digest Algorithm</a>",
 *        IETF RFC-1320 (informational).
 * </ol>
 *
 * <p><b>$Revision: 1.2 $</b>
 * @author  Raif S. Naffah
 */

 * {@link CrawlerContainer}, {@link LogHelper}, {@link CrawlerClientFactory}, and {@link CrawlerContext},
 * to perform its tasks.
 * </p>
 *
 * <p>
 * The crawling process involves the following steps:
 * </p>
 * <ol>
 *   <li>Fetching a URL from the queue using {@link UrlQueueService#poll(String)}.</li>
 *   <li>Checking if the URL is valid using {@link #isValid(UrlQueue)}.</li>

 * lookups.
 *
 * <p>During construction, names are normalized in two ways:
 *
 * <ol>
 *   <li>ASCII uppercase characters are converted to lowercase.
 *   <li>Unicode dot separators other than the ASCII period ({@code '.'}) are converted to the ASCII
 *       period.
 * </ol>
 *
 * <p>The normalized values will be returned from {@link #toString()} and {@link #parts()}, and will

m&a&rah?vk??f!.sg??h!.sg??i&e&h&dnort?rtsua?ssej??rkrejb??ksa??ol?t!.sg??u&dom?esum?r&ab?drejg?evle?os?uh?æb?øs??ttals???n&a&g&av?okssman?åv??jlis?or?r&g?rev???e&d&do&sen?ton??lah?r&agy&o?ø??ojfsam???g&iets?n&a&l&as?lab??n&avk?ævk??t&arg?ddosen??v&al?essov???i&d&ol?øl??l&ar?ær???yl??reb??iks?k&srot?y&or?ør???l&a&d&gnos?n&er?ojm?øjm??om??tloh??ug?åtloh??mmard?ojs&om?sendnas??ppolg?s&lahsladr&ojts?øjts??o??t&o&l?t-erts&ev?o?ø???roh?øl??vly&kkys?nav??yam-naj!.sg??øjs&om?sendnas???g&orf?ujb??i&dnaor...

 *     <li><code>alpha</code> or <code>a</code></li>
 *     <li><code>beta</code> or <code>b</code></li>
 *     <li><code>milestone</code> or <code>m</code></li>
 *     <li><code>rc</code> or <code>cr</code></li>
 *     <li><code>snapshot</code></li>
 *     <li><code>ga</code> or <code>final</code></li>
 *     <li><code>sp</code></li>
 *     </ol>

  static byte[] createBuffer() {
    return new byte[BUFFER_SIZE];
  }

  /**
   * There are three methods to implement {@link FileChannel#transferTo(long, long,
   * WritableByteChannel)}:
   *
   * <ol>
   *   <li>Use sendfile(2) or equivalent. Requires that both the input channel and the output
   *       channel have their own file descriptors. Generally this only happens when both channels

<i>W</i>(<i>r</i>) must be a write <i>w</i> that is <i>visible</i> to <i>r</i>,
where visible means that both of the following hold:
</p>

<ol>
	<li><i>w</i> happens before <i>r</i>.</li>
	<li><i>w</i> does not happen before any other write <i>w'</i> (to <i>x</i>) that happens before <i>r</i>.</li>
</ol>

<p>
A <i>read-write data race</i> on memory location <i>x</i>
consists of a read-like memory operation <i>r</i> on <i>x</i>

 * is by declaring that step to be the last step of the pipeline. Nevertheless, we refer to the
 * "value" of a successful step or the "result" (value or exception) of any step.
 *
 * <ol>
 *   <li>A pipeline starts at its leaf step (or steps), which is created from either a callable
 *       block or a {@link ListenableFuture}.