* on the queue the longest time. The tail of the queue is that element that has been on
 * the queue the shortest time. New elements are inserted at the tail of the queue, and the queue
 * retrieval operations obtain elements at the head of the queue.
 *
 * <p>This is a classic &quot;bounded buffer&quot;, in which a fixed-sized array holds elements

        } catch (final ExecutionException e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Failed to retrieval a cache.", e);
            }
            return new XPathAPI();
        }
    }

    /**
     * Returns the header for the result data.
     * @return The result data header.
     */
    protected String getResultDataHeader() {
        // TODO support other type

    }

    /**
     * Retrieves a single document from the OpenSearch index by session ID and URL.
     *
     * @param <T> The type of the object to retrieve.
     * @param clazz The class of the object to retrieve.
     * @param sessionId The session ID of the document.
     * @param url The URL of the document.
     * @return The retrieved object, or null if not found.

 * <ul>
 *   <li>chaining methods which return a new {@code FluentIterable} based in some way on the
 *       contents of the current one (for example {@link #transform})
 *   <li>element extraction methods which facilitate the retrieval of certain elements (for example
 *       {@link #last})
 *   <li>query methods which answer questions about the {@code FluentIterable}'s contents (for
 *       example {@link #anyMatch})

 * <ul>
 *   <li>chaining methods which return a new {@code FluentIterable} based in some way on the
 *       contents of the current one (for example {@link #transform})
 *   <li>element extraction methods which facilitate the retrieval of certain elements (for example
 *       {@link #last})
 *   <li>query methods which answer questions about the {@code FluentIterable}'s contents (for
 *       example {@link #anyMatch})

    }

    /**
     * Creates a stream response for document content delivery.
     * Handles content retrieval and streaming to the client.
     *
     * @param doc the document data map
     * @return the stream response containing document content
     * @throws FessSystemException if content cannot be retrieved
     */
    public StreamResponse asContentResponse(final Map<String, Object> doc) {

    NetbiosAddress getNbtByName(String host) throws UnknownHostException;

    /**
     * Retrieves the node status information for the specified NetBIOS address.
     *
     * @param nbtAddress the NetBIOS address to query
     * @return the node status responses
     * @throws UnknownHostException if the node status cannot be retrieved
     */
    NetbiosAddress[] getNodeStatus(NetbiosAddress nbtAddress) throws UnknownHostException;

        params.put(key, value);
    }

    /**
     * Retrieves a parameter value by key.
     *
     * @param key the parameter key to look up
     * @return the parameter value if found, null otherwise
     */
    public Object get(final String key) {
        return params.get(key);
    }

    /**
     * Retrieves a parameter value as a String.

        }
        return configId.substring(1);
    }

    /**
     * Retrieves a crawling configuration by its config ID.
     * This method uses caching to improve performance and automatically determines
     * the configuration type and delegates to the appropriate service.
     *
     * @param configId the configuration ID to retrieve
     * @return the CrawlingConfig object or null if not found or on error
     */

     * address, isPermanent, isBeingDeleted, ...etc. This information can only
     * be retrieved with the Node Status request.
     *
     * The degree of state that an NbtAddress has is dependant on how it was
     * created and what is required of it. The second degree of state is the
     * most common. This is the state information that would be retrieved from
     * WINS for example. Natrually it is not practical for every NbtAddress