}

  private static final class JdkMatcher extends CommonMatcher {
    final Matcher matcher;

    JdkMatcher(Matcher matcher) {
      this.matcher = Preconditions.checkNotNull(matcher);
    }

    @Override
    public boolean matches() {
      return matcher.matches();
    }

    @Override
    public boolean find() {
      return matcher.find();
    }

    @Override
    public boolean find(int index) {

    checkArgument(
        !separatorPattern.matcher("").matches(),
        "The pattern may not match the empty string: %s",
        separatorPattern);

    return new Splitter(
        new Strategy() {
          @Override
          public SplittingIterator iterator(final Splitter splitter, CharSequence toSplit) {
            final CommonMatcher matcher = separatorPattern.matcher(toSplit);

          dayOfMonth == -1 && matcher.usePattern(DAY_OF_MONTH_PATTERN).matches() -> {
            dayOfMonth = matcher.group(1).toInt()
          }
          month == -1 && matcher.usePattern(MONTH_PATTERN).matches() -> {
            val monthString = matcher.group(1).lowercase(Locale.US)
            month = MONTH_PATTERN.pattern().indexOf(monthString) / 4 // Sneaky! jan=1, dec=12.
          }

  // matches only a single label. You cannot have a wildcard label by itself (e.g. Host == "*").
  // Requests will be matched against the Host field in the following way:
  // 1. If Host is precise, the request matches this rule if the http host header is equal to Host.
  // 2. If Host is a wildcard, then the request matches this rule if the http host header

  // matches only a single label. You cannot have a wildcard label by itself (e.g. Host == "*").
  // Requests will be matched against the Host field in the following way:
  // 1. If host is precise, the request matches this rule if the http host header is equal to Host.
  // 2. If host is a wildcard, then the request matches this rule if the http host header

    private static String unQuoteUnEscape(final String original) {
        String result = original;

        // Unquote
        if (result.indexOf('\"') >= 0) {
            final Matcher m = QUOTE_REPLACE_PATTERN.matcher(original);
            if (m.matches()) {
                result = m.group(1);
            }

            // Unescape
            if (result.indexOf(ESCAPED_QUOTE) >= 0) {

/**
 * The subset of the {@link java.util.regex.Matcher} API which is used by this package, and also
 * shared with the {@code re2j} library. For internal use only. Please refer to the {@code Matcher}
 * javadoc for details.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonMatcher {
  public abstract boolean matches();

  public abstract boolean find();

            throw new RobotsTxtException("Failed to parse robots.txt.", e);
        }
    }

    protected String getValue(final Pattern pattern, final String line) {
        final Matcher m = pattern.matcher(line);
        if (m.matches() && m.groupCount() > 0) {
            return m.group(1);
        }
        return null;
    }

    protected String stripComment(final String line) {

            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                String filename = file.getFileName().toString();
                if (mavenArtifactJar.matcher(filename).matches()) {
                    Process p = Runtime.getRuntime().exec(new String[] {
                        Paths.get(System.getProperty("java.home"), "bin/java").toString(),
                        "-jar",

                        if (pos < line.length()) {
                            String data = line.substring(pos + 1).trim();
                            if (properyPattern.matcher(key).matches() && data.startsWith(CIPHER_PREFIX)) {
                                data = cipher.decrypt(data.substring(CIPHER_PREFIX.length()));
                            }
                            paramMap.put(key, data);