InetAddress ip = InetAddresses.forString(validIsatapAddress);
      assertTrue(InetAddresses.isIsatapAddress((Inet6Address) ip));
      assertEquals(
          "checking '" + validIsatapAddress + "'",
          ipv4,
          InetAddresses.getIsatapIPv4Address((Inet6Address) ip));
    }
    for (String nonIsatapAddress : nonIsatapAddresses) {
      InetAddress ip = InetAddresses.forString(nonIsatapAddress);

            .buildOrThrow();
    ImmutableSet<String> uppercaseAcronyms =
        ImmutableSet.of(
            "CH", "ID", "DNT", "DNS", "DPR", "ECT", "HTTP2", "IP", "MD5", "P3P", "RTT", "TE", "UA",
            "UID", "URL", "WWW", "XSS");
    assertConstantNameMatchesString(HttpHeaders.class, specialCases, uppercaseAcronyms);
  }

  // Visible for other tests to use

            .buildOrThrow();
    ImmutableSet<String> uppercaseAcronyms =
        ImmutableSet.of(
            "CH", "ID", "DNT", "DNS", "DPR", "ECT", "GPC", "HTTP2", "IP", "MD5", "P3P", "RTT", "TE",
            "UA", "UID", "URL", "WWW", "XSS");
    assertConstantNameMatchesString(HttpHeaders.class, specialCases, uppercaseAcronyms);
  }

  // Visible for other tests to use

   * disallow IPv6 literals that don't contain these brackets.
   *
   * <p>Note that this parser identifies IPv6 literals solely based on the presence of a colon. To
   * perform actual validation of IP addresses, see the {@link InetAddresses#forString(String)}
   * method.
   *
   * @return {@code this}, to enable chaining of calls.
   * @throws IllegalArgumentException if bracketless IPv6 is detected.
   */

   * href="https://iabtechlab.com/wp-content/uploads/2019/06/VAST_4.2_final_june26.pdf">{@code
   * X-Device-IP}</a> header field name. Header used for VAST requests to provide the IP address of
   * the device on whose behalf the request is being made.
   *
   * @since 31.0
   */
  public static final String X_DEVICE_IP = "X-Device-IP";
  /**
   * The HTTP <a

   * such as "::c000:201". The output does not include a Scope ID.
   *
   * @param ip {@link InetAddress} to be converted to an address string
   * @return {@code String} containing the text-formatted IP address
   * @since 10.0
   */
  public static String toAddrString(InetAddress ip) {
    checkNotNull(ip);
    if (ip instanceof Inet4Address) {
      // For IPv4, Java's formatting is good enough.

      InetAddress ip = InetAddresses.forString(validIsatapAddress);
      assertTrue(InetAddresses.isIsatapAddress((Inet6Address) ip));
      assertEquals(
          "checking '" + validIsatapAddress + "'",
          ipv4,
          InetAddresses.getIsatapIPv4Address((Inet6Address) ip));
    }
    for (String nonIsatapAddress : nonIsatapAddresses) {
      InetAddress ip = InetAddresses.forString(nonIsatapAddress);

   *   <li>Parts other than the final part may start with a digit, as mandated by <a
   *       href="https://tools.ietf.org/html/rfc1123#section-2">RFC 1123</a>.
   * </ul>
   *
   * @param domain A domain name (not IP address)
   * @throws IllegalArgumentException if {@code domain} is not syntactically valid according to
   *     {@link #isValid}
   * @since 10.0 (previously named {@code fromLenient})
   */

      ImmutableSet.of("foo.bar.google.com", "a.b.co.uk", "x.y.ca.us", "a.b.blogspot.com");

  private static final ImmutableSet<String> VALID_IP_ADDRS =
      ImmutableSet.of("1.2.3.4", "127.0.0.1", "::1", "2001:db8::1");

  private static final ImmutableSet<String> INVALID_IP_ADDRS =
      ImmutableSet.of(
          "", "1", "1.2.3", "...", "1.2.3.4.5", "400.500.600.700", ":", ":::1", "2001:db8:");

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Utility methods and classes for networking (such as IP addresses and domain names).
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 *
 * @author Craig Berry
 */
@CheckReturnValue