* Pattern for HTML tags.
     */
    protected Pattern htmlTagPattern = Pattern.compile("<[^>]+>");

    /** Map of parser features. */
    protected Map<String, String> featureMap = new HashMap<>();

    /** Map of parser properties. */
    protected Map<String, String> propertyMap = new HashMap<>();

    /** XPath expression for extracting content from the document body. */
    protected String contentXpath = "//BODY";

    /**
     * Map of pending requests to their corresponding responses.
     */
    protected HashMap response_map = new HashMap(4);

    /**
     * Creates a key for the specified request for response matching.
     *
     * @param request the request to create a key for
     * @throws IOException if an I/O error occurs
     */
    protected abstract void makeKey(Request request) throws IOException;

    /**

     * directory.
     */
    protected String path;

    /**
     * A string to replace ?.
     */
    protected String questionStr = "_QUEST_";

    /**
     * A string to replace :.
     */
    protected String colonStr = "_CLN_";

    /**
     * A string to replace ;.
     */
    protected String semicolonStr = "_SCLN_";

    /**
     * A string to replace &.

    static final byte TRANS_TRANSACT_NAMED_PIPE = (byte) 0x26;

    protected int primarySetupOffset;
    protected int secondaryParameterOffset;
    protected int parameterCount;
    protected int parameterOffset;
    protected int parameterDisplacement;
    protected int dataCount;
    protected int dataOffset;
    protected int dataDisplacement;

    int totalParameterCount;
    int totalDataCount;

    /** User agent string */
    protected String userAgent = "Crawler";

    /** HTTP client context for requests */
    protected HttpClientContext httpClientContext = HttpClientContext.create();

    /** Proxy host name */
    protected String proxyHost;

    /** Proxy port number */
    protected Integer proxyPort;

    /** Proxy authentication scheme */
    protected AuthScheme proxyAuthScheme = new BasicScheme();

    /** Configuration key for SPNEGO initialization status. */
    protected static final String SPNEGO_INITIALIZED = "spnego.initialized";

    /** Configuration key for directories to exclude from SPNEGO authentication. */
    protected static final String SPNEGO_EXCLUDE_DIRS = "spnego.exclude.dirs";

    /** Configuration key for enabling delegation in SPNEGO authentication. */

    public static class IntervalRule {
        /** Starting hour of the interval */
        protected int fromHours;

        /** Starting minute of the interval */
        protected int fromMinutes;

        /** Ending hour of the interval */
        protected int toHours;

        /** Ending minute of the interval */
        protected int toMinutes;

        /** Delay in milliseconds to apply during this interval */

    /**
     * Queue index name.
     */
    protected String queueIndex = ".crawler.queue";

    /**
     * Data index name.
     */
    protected String dataIndex = ".crawler.data";

    /**
     * Filter index name.
     */
    protected String filterIndex = ".crawler.filter";

    /**
     * Number of shards for the queue index.
     */

        return this.lastName;
    }

    @Override
    protected int writeSetupWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

    @Override
    protected int writeParametersWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

    @Override
    protected int writeDataWireFormat(final byte[] dst, final int dstIndex) {
        return 0;
    }

     * in configuration or processing logic.
     */
    protected static final String URL_EXCLUDE_PATTERN = "url_exclude_pattern";

    /** The underlying index update callback to delegate operations to. */
    protected IndexUpdateCallback indexUpdateCallback;

    /** Factory for creating crawler clients to handle different URL schemes. */
    protected CrawlerClientFactory crawlerClientFactory;