*
 * <ul>
 *   <li><a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a>
 *   <li><a href="http://www.ietf.org/rfc/rfc2183.txt">RFC 2183</a>
 *   <li><a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a>
 *   <li><a href="http://www.ietf.org/rfc/rfc2965.txt">RFC 2965</a>
 *   <li><a href="http://www.ietf.org/rfc/rfc5988.txt">RFC 5988</a>
 * </ul>
 *
 * @author Kurt Alfred Kluever
 * @since 11.0
 */

  /**
   * The "base64" base encoding specified by <a
   * href="http://tools.ietf.org/html/rfc4648#section-4">RFC 4648 section 4</a>, Base 64 Encoding.
   * (This is the same as the base 64 encoding from <a
   * href="http://tools.ietf.org/html/rfc3548#section-3">RFC 3548</a>.)
   *
   * <p>The character {@code '='} is used for padding, but can be {@linkplain #omitPadding()

   * label. See <a href="http://www.ietf.org/rfc/rfc2181.txt">RFC 2181</a> part 11.
   */
  private static final int MAX_LENGTH = 253;

  /**
   * Maximum size of a single part of a domain name. See <a
   * href="http://www.ietf.org/rfc/rfc2181.txt">RFC 2181</a> part 11.
   */
  private static final int MAX_DOMAIN_PART_LENGTH = 63;

   * href="http://en.wikipedia.org/wiki/Teredo_tunneling">http://en.wikipedia.
   * org/wiki/Teredo_tunneling</a>.
   *
   * <p>The RFC can be found here: <a target="_parent" href="http://tools.ietf.org/html/rfc4380">RFC
   * 4380</a>.
   *
   * @since 5.0
   */
  public static final class TeredoInfo {
    private final Inet4Address server;
    private final Inet4Address client;

        + ", format="
        + key.getFormat()
        + "])";
  }

  /**
   * Returns a hash function implementing the CRC32C checksum algorithm (32 hash bits) as described
   * by RFC 3720, Section 12.1.
   *
   * <p>This function is best understood as a <a
   * href="https://en.wikipedia.org/wiki/Checksum">checksum</a> rather than a true <a