* Caffeine}</a> class. Caffeine offers better performance, more features (including asynchronous
 * loading), and fewer <a
 * href="https://github.com/google/guava/issues?q=is%3Aopen+is%3Aissue+label%3Apackage%3Dcache+label%3Atype%3Ddefect">bugs</a>.
 *
 * <p>Caffeine defines its own interfaces (<a

import jakarta.annotation.Resource;
import jakarta.servlet.http.HttpServletRequest;

/**
 * Client class for RAG (Retrieval-Augmented Generation) chat functionality.
 *
 * Orchestrates the multi-phase RAG workflow including session management,
 * document search, and delegation to LlmClientManager for LLM operations.
 * Prompt construction and LLM-specific logic is handled by LlmClient implementations.
 *
 * @author FessProject
 */

 * Caffeine}</a> class. Caffeine offers better performance, more features (including asynchronous
 * loading), and fewer <a
 * href="https://github.com/google/guava/issues?q=is%3Aopen+is%3Aissue+label%3Apackage%3Dcache+label%3Atype%3Ddefect">bugs</a>.
 *
 * <p>Caffeine defines its own interfaces (<a

     * values must be between 1 and [Integer.MAX_VALUE] when converted to milliseconds.
     *
     * The read timeout is applied to both the TCP socket and for individual read IO operations
     * including on [Source] of the [Response]. The default value is 10 seconds.
     *
     * @see Socket.setSoTimeout
     * @see Source.timeout
     */
    fun readTimeout(
      timeout: Long,
      unit: TimeUnit,

 * <a href="http://www.unicode.org/glossary/#supplementary_code_point">supplementary Unicode code
 * points</a> in the range {@code 0x10000} to {@code 0x10FFFF} which includes the majority of
 * assigned characters, including important CJK characters and emoji.
 *
 * <p>Supplementary characters are <a
 * href="https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/Character.html#supplementary">encoded

/**
 * Hc4HttpClient is an HTTP client implementation using Apache HttpComponents 4.x.
 * It extends {@link HcHttpClient} and provides various configurations and settings
 * for making HTTP requests, including connection timeouts, proxy settings, user agent,
 * request headers, cookie management, and SSL configurations. The client also supports
 * robots.txt parsing and form-based authentication schemes.
 *
 * @see HcHttpClient

 * <a href="http://www.unicode.org/glossary/#supplementary_code_point">supplementary Unicode code
 * points</a> in the range {@code 0x10000} to {@code 0x10FFFF} which includes the majority of
 * assigned characters, including important CJK characters and emoji.
 *
 * <p>Supplementary characters are <a
 * href="https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/Character.html#supplementary">encoded

/**
 * A transformer implementation for processing HTML documents using XPath expressions.
 * This class extends XpathTransformer to provide Fess-specific document processing capabilities
 * including content extraction, metadata processing, and robots tag handling.
 */
public class FessXpathTransformer extends XpathTransformer implements FessTransformer {

    /** Logger instance for this class */

/**
 * Hc5HttpClient is an HTTP client implementation using Apache HttpComponents 5.x.
 * It extends {@link HcHttpClient} and provides various configurations and settings
 * for making HTTP requests, including connection timeouts, proxy settings, user agent,
 * request headers, cookie management, and SSL configurations. The client also supports
 * robots.txt parsing and form-based authentication schemes.
 *
 * @see HcHttpClient

// Adds a copy of function `func` and optionally its gradient function `grad`
// to `g`. Once `func`/`grad` is added to `g`, it can be called by creating
// an operation using the function's name.
// Any changes to `func`/`grad` (including deleting it) done after this method
// returns, won't affect the copy of `func`/`grad` in `g`.
// If `func` or `grad` are already in `g`, TF_GraphCopyFunction has no