func newSignV4ChunkedReader(req *http.Request, trailer bool) (io.ReadCloser, APIErrorCode) {
	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}

    @DisplayName("writeWireFormat should write header and trailer")
    void testWriteWireFormat() {
        packet.type = SessionServicePacket.SESSION_MESSAGE;
        packet.trailerLength = 10; // Mock trailer will write 10 bytes

        byte[] dst = new byte[50];
        int totalWritten = packet.writeWireFormat(dst, 0);

        assertEquals(14, totalWritten); // 4 header + 10 trailer

	cs, err := GetContentChecksum(req.Header)
	if err != nil {
		return ErrInvalidChecksum
	}
	if cs == nil {
		return nil
	}
	r.contentHash = *cs
	if cs.Type.Trailing() {
		r.trailer = req.Trailer
	}
	return r.AddNonTrailingChecksum(cs, ignoreValue)
}

// AddChecksumNoTrailer will add checksum checks as specified in
// https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html

	AmzCredential           = "X-Amz-Credential"
	AmzSecurityToken        = "X-Amz-Security-Token"
	AmzDecodedContentLength = "X-Amz-Decoded-Content-Length"
	AmzTrailer              = "X-Amz-Trailer"
	AmzMaxParts             = "X-Amz-Max-Parts"
	AmzPartNumberMarker     = "X-Amz-Part-Number-Marker"

	// Constants used for GetObjectAttributes and GetObjectVersionAttributes

   * Timing-Allow-Origin}</a> header field name.
   *
   * @since 15.0
   */
  public static final String TIMING_ALLOW_ORIGIN = "Timing-Allow-Origin";

  /** The HTTP {@code Trailer} header field name. */
  public static final String TRAILER = "Trailer";

  /** The HTTP {@code Transfer-Encoding} header field name. */
  public static final String TRANSFER_ENCODING = "Transfer-Encoding";

// If checksum was trailing, they must have been added to r.Trailer.
func TransferChecksumHeader(w http.ResponseWriter, r *http.Request) {
	c, err := GetContentChecksum(r.Header)
	if err != nil || c == nil {
		return
	}
	t, s := c.Type, c.Encoded
	if !c.Type.IsSet() {
		return
	}
	if c.Type.Is(ChecksumTrailing) {
		val := r.Trailer.Get(t.Key())
		if val != "" {
			w.Header().Set(t.Key(), val)
		}

	return r.Header.Get(xhttp.AmzContentSha256) == streamingContentSHA256Trailer &&
		r.Method == http.MethodPut
}

// Verify if the request has AWS Streaming Signature Version '4', with unsigned content and trailer.
func isRequestUnsignedTrailerV4(r *http.Request) bool {
	return r.Header.Get(xhttp.AmzContentSha256) == unsignedPayloadTrailer &&
		r.Method == http.MethodPut
}

// Authorization type.
//

 *
 * <p>Example usage:
 * <pre>
 *   Crawler crawler = new Crawler();
 *   crawler.addUrl("http://example.com/");
 *   crawler.execute();
 *   crawler.close();
 * </pre>
 */
public class Crawler implements Runnable, AutoCloseable {

    private static final Logger logger = LogManager.getLogger(Crawler.class);

    /**
     * Service for managing URL queues during crawling.
     */

 * </pre>
 */
public class Crawler {

    /**
     * Creates a new instance of Crawler.
     */
    public Crawler() {
        // Default constructor
    }

    /** Logger instance for this class. */
    private static final Logger logger = LogManager.getLogger(Crawler.class);

    /** Thread name for web and file system crawling process. */

 */
package org.codelibs.fess.crawler;

import java.io.File;

import org.codelibs.core.io.ResourceUtil;
import org.codelibs.fess.crawler.container.CrawlerContainer;
import org.codelibs.fess.crawler.entity.UrlQueue;
import org.codelibs.fess.crawler.filter.impl.UrlFilterImpl;
import org.codelibs.fess.crawler.service.DataService;
import org.codelibs.fess.crawler.service.UrlQueueService;