private enum DfsState {
        VISITING,
        VISITED
    }

    final Map<String, Vertex> vertices = new LinkedHashMap<>();

    public Vertex getVertex(String id) {
        return vertices.get(id);
    }

    public Collection<Vertex> getVertices() {
        return vertices.values();
    }

    Vertex addVertex(String label) {
        return vertices.computeIfAbsent(label, Vertex::new);
    }

    }

    /**
     * Sets the headers for the response.
     *
     * @param headers the headers to set.
     */
    public void setHeaders(final Map<String, List<String>> headers) {
        if (headers != null) {
            final Map<String, List<String>> map = new HashMap<>();
            headers.entrySet().stream().filter(e -> e.getKey() != null).forEach(

     */
    protected Map<String, String> convertMap = new LinkedHashMap<>();

    /**
     * Converts a URL.
     *
     * @param url The URL.
     * @return A converted URL.
     */
    public String convert(final String url) {
        if (url == null) {
            return null;
        }
        String convertedUrl = url;
        for (final Map.Entry<String, String> entry : convertMap.entrySet()) {

    class AuthenticationMetadata {
        private final String username;
        private final String domain;
        private final AuthType authType;
        private final long timestamp;
        private final String clientAddress;
        private final String serverAddress;

        public AuthenticationMetadata(String username, String domain, AuthType authType, String clientAddress, String serverAddress) {
            this.username = username;

@Deprecated(since = "4.0.0")
public class ArtifactModelSource extends FileSource implements ModelSource {
    private final String groupId;

    private final String artifactId;

    private final String version;

    private final int hashCode;

    @Deprecated
    public ArtifactModelSource(File file, String groupId, String artifactId, String version) {
        super(file);
        this.groupId = groupId;
        this.artifactId = artifactId;

            final int num = 100000;
            final Map<String, String> hmap = new HashMap<String, String>();
            final Map<String, String> cimap = new CaseInsensitiveMap<String>();

            long start = System.currentTimeMillis();
            for (int i = 0; i < num; i++) {
                hmap.put("a" + String.valueOf(i), null);
            }

    public static String getProperty(String key) {
        return System.getProperty(key);
    }

    /**
     * Returns the system property value for the specified key, or the default value if not found.
     *
     * @param key the property key
     * @param defaultValue the default value
     * @return the property value, or the default value if not found
     */
    public static String getProperty(String key, String defaultValue) {

        /** Bug report properties. */
        protected List<Map<String, String>> bugReportProps;

        /**
         * Sets the environment properties.
         * @param envProps The environment properties.
         * @return This ApiSystemInfoResponse instance.
         */
        public ApiSystemInfoResponse envProps(final List<Map<String, String>> envProps) {
            this.envProps = envProps;

        MapTestSuiteBuilder.using(
                new TestStringMapGenerator() {
                  @Override
                  protected Map<String, String> create(Entry<String, String>[] entries) {
                    Map<String, String> map = CompactLinkedHashMap.create();
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;

        document.accept(visitor);

        final Map<String, List<String>> frontMatter = visitor.getData();
        for (final Map.Entry<String, List<String>> entry : frontMatter.entrySet()) {
            final String key = "frontmatter." + entry.getKey();
            final List<String> values = entry.getValue();
            if (values != null && !values.isEmpty()) {