UrlQueueImpl<Long> queue = new UrlQueueImpl<>();

        String metaData = "{\"key\":\"value\"}";
        queue.setMetaData(metaData);
        assertEquals(metaData, queue.getMetaData());

        queue.setMetaData(null);
        assertNull(queue.getMetaData());
    }

    public void test_encodingGetterSetter() {
        // Test encoding getter/setter

     * Retrieves the metadata associated with the URL queue.
     *
     * @return a String representing the metadata.
     */
    String getMetaData();

    /**
     * Sets the metadata for the URL queue.
     *
     * @param metaData the metadata to set
     */
    void setMetaData(String metaData);

    /**
     * Retrieves the encoding of the URL queue.
     *
     * @return the encoding as a String.
     */

     */
    @Override
    public void setUrl(final String url) {
        this.url = url;
    }

    @Override
    public String getMetaData() {
        return metaData;
    }

    @Override
    public void setMetaData(final String metaData) {
        this.metaData = metaData;
    }

    @Override
    public String getEncoding() {
        return encoding;
    }

     */
    void clearSensitiveData();

    /**
     * Gets authentication metadata for auditing
     *
     * @return authentication metadata
     */
    AuthenticationMetadata getMetadata();

    /**
     * Authentication metadata for auditing and logging
     */
    class AuthenticationMetadata {
        private final String username;
        private final String domain;