* @return A new {@code UnaryOperator<String>} that caches the results of the original function.
     *         If the original function returns null for a given input, null will be cached and returned for subsequent calls with the same input.
     *
     * @see Function
     * @see Optional
     * @see HashMap#computeIfAbsent(Object, Function)
     */

- **Utility Classes** - All core functionality exposed through static utility methods for easy access

### Performance Optimizations
- **Caching** - Bean descriptors and reflection metadata are cached for improved performance
- **Lazy initialization** - Resources and expensive operations are initialized only when needed  

import org.codelibs.fess.crawler.util.FieldConfigs;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;

/**
 * Interface for transforming and processing crawled documents in Fess.
 * Provides utility methods for URL processing, site extraction, data mapping,
 * and field configuration handling during the document transformation process.
 */
public interface FessTransformer {

        } finally {
            limitedManager.shutdown();
        }
    }

    @Test
    @DisplayName("Should register and manage file cache")
    void testFileCache() {
        String path = "/share/cached.txt";
        Smb2LeaseKey key = leaseManager.requestLease(path, Smb2LeaseState.SMB2_LEASE_FULL);

        // Register a mock file with cache

 * handshakes.
 */
class Handshake internal constructor(
  /**
   * Returns the TLS version used for this connection. This value wasn't tracked prior to OkHttp
   * 3.0. For responses cached by preceding versions this returns [TlsVersion.SSL_3_0].
   */
  @get:JvmName("tlsVersion") val tlsVersion: TlsVersion,
  /** Returns the cipher suite used for the connection. */

 * This class defines tag patterns that match HTML elements based on tag name, CSS class, ID, or custom attributes.
 * It is used to identify and remove unwanted HTML elements from crawled documents.
 */
public class PrunedTag {
    /** The HTML tag name to match (e.g., "div", "span", "p") */
    private final String tag;
    /** The ID attribute value to match */
    private String id;

   * effect.
   *
   * <p>This method is equivalent to {@code put(rowKey, columnKey, null)} when both provided keys
   * are valid.
   *
   * @param rowKey row key of mapping to be erased
   * @param columnKey column key of mapping to be erased
   * @return the value previously associated with the keys, or {@code null} if no mapping existed
   *     for the keys
   */
  @CanIgnoreReturnValue

    @ParameterizedTest
    @ValueSource(strings = { "none", "No_Retry", "retain_payload", "UNKNOWN", "NO-RETRY" })
    @DisplayName("valueOf with unknown or differently-cased names throws IllegalArgumentException")
    void valueOfRejectsUnknownOrCaseMismatch(String badName) {
        IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () -> RequestParam.valueOf(badName));

  }

  // Verify that StackOverflowError in a long chain of SetFuture doesn't cause the entire toString
  // call to fail
  @J2ktIncompatible
  @GwtIncompatible
  @AndroidIncompatible // b/391667564: crashes from stack overflows
  public void testSetFutureToString_stackOverflow() {
    SettableFuture<String> orig = SettableFuture.create();
    SettableFuture<String> prev = orig;
    for (int i = 0; i < 100000; i++) {

            String newValue = "changed";
            System.setProperty(Constants.FESS_CONFIG_PREFIX + testKey, newValue);

            // Get value again - in real FessConfigImpl it would be cached,
            // but our test implementation always checks system properties
            String value2 = fessConfig.get(testKey);
            // In our test implementation, it will pick up the new value