* characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *
   * <p>The scope ID is validated against the interfaces on the machine, which requires permissions
   * under Android.
   *

   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *
   * <p>The scope ID is validated against the interfaces on the machine, which requires permissions
   * under Android.
   *

  private static String normalizeToken(String token) {
    checkArgument(TOKEN_MATCHER.matchesAllOf(token));
    checkArgument(!token.isEmpty());
    return Ascii.toLowerCase(token);
  }

  private static String normalizeParameterValue(String attribute, String value) {
    checkNotNull(value); // for GWT
    checkArgument(ascii().matchesAllOf(value), "parameter values must be ASCII: %s", value);

  private static String normalizeToken(String token) {
    checkArgument(TOKEN_MATCHER.matchesAllOf(token));
    checkArgument(!token.isEmpty());
    return Ascii.toLowerCase(token);
  }

  private static String normalizeParameterValue(String attribute, String value) {
    checkNotNull(value); // for GWT
    checkArgument(ascii().matchesAllOf(value), "parameter values must be ASCII: %s", value);

     * being allowed due to widespread practice.
     */

    String asciiChars = CharMatcher.ascii().retainFrom(part);

    if (!PART_CHAR_MATCHER.matchesAllOf(asciiChars)) {
      return false;
    }

    // No initial or final dashes or underscores.

    if (DASH_MATCHER.matches(part.charAt(0))
        || DASH_MATCHER.matches(part.charAt(part.length() - 1))) {