RequirementMatcher matcher;
        matcher = RequirementMatcherFactory.createVersionMatcher("1.5.2");
        assertFalse(matcher.matches("1.5"));
        assertTrue(matcher.matches("1.5.2"));
        assertFalse(matcher.matches("[1.4,1.5)"));
        assertFalse(matcher.matches("[1.5,1.5.2)"));
        assertFalse(matcher.matches("(1.5.2,1.6)"));
        assertTrue(matcher.matches("(1.4,1.5.2]"));

            if (obj != null) {
                value = obj.toString();
            }
            final Matcher matcher = entry.getValue().matcher(value);
            if (allRequired) {
                if (!matcher.matches()) {
                    return false;
                }
            } else if (matcher.matches()) {
                return true;
            }
        }

        return allRequired;
    }

                final Matcher matcher = pattern.matcher(url);
                if (matcher.matches()) {
                    match = true;
                }
            }
            if (!match) {
                return false;
            }
        }

        if (!excludeList.isEmpty()) {
            boolean match = false;
            for (final Pattern pattern : excludeList) {

        if (lastHyphen > 0) {
            int prevHyphen = version.lastIndexOf('-', lastHyphen - 1);
            if (prevHyphen > 0) {
                Matcher m = Artifact.VERSION_FILE_PATTERN.matcher(version);
                if (m.matches()) {
                    return m.group(1) + "-" + Artifact.SNAPSHOT_VERSION;
                }
            }
        }
        return version;
    }

        for (final Map.Entry<Pattern, CrawlerClient> entry : clientMap.entrySet()) {
            final Matcher matcher = entry.getKey().matcher(urlKey);
            if (matcher.matches()) {
                return entry.getValue();
            }
        }
        return null;
    }

    /**
     * Sets the initialization parameter map for all clients.
     * @param params The map of parameters.
     */

    /**
     * {@return whether the given matcher includes all files}.
     * This method may conservatively returns {@code false} if case of doubt.
     * A return value of {@code true} means that the pattern is certain to match all files.
     *
     * @param matcher the matcher to test
     */
    default boolean isIncludesAll(@Nonnull PathMatcher matcher) {
        return Objects.requireNonNull(matcher) == includesAll();
    }

        provides.put(type, matcher);
    }

    @Override
    public boolean matchesRequirements(Map<String, String> requirements) {
        for (Map.Entry<String, String> requirement : requirements.entrySet()) {
            String key = requirement.getKey();

            RequirementMatcher matcher = provides.get(key);

            if (matcher == null) {

            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",

     * @param pattern the pattern to match against
     * @param line the line to extract the value from
     * @return the extracted value, or null if no match
     */
    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);
        }

            if (artifact.isSnapshot()) {
                Matcher matcher = Artifact.VERSION_FILE_PATTERN.matcher(artifact.getVersion());
                if (matcher.matches()) {
                    Snapshot snapshot = new Snapshot();
                    snapshot.setTimestamp(matcher.group(2));
                    try {
                        snapshot.setBuildNumber(Integer.parseInt(matcher.group(3)));