assertEquals((byte) 0x00, buf[2], "Reserved byte must be 0");
        assertEquals((byte) 0xDE, buf[3], "Sentinel low offset when no chaining");
        assertEquals((byte) 0xDE, buf[4], "Sentinel high offset when no chaining");
        assertNull(block.andx, "andx should be cleared when not chaining");
    }

    @Test

		return etag
	}
	return ""
}

// Beginning of unix time is treated as sentinel value here.
var (
	timeSentinel     = time.Unix(0, 0).UTC()
	timeSentinel1970 = time.Unix(0, 1).UTC() // 1970 used for special cases when xlmeta.version == 0
)

// Boot modTimes up to disk count, setting the value to time sentinel.
func bootModtimes(diskCount int) []time.Time {
	modTimes := make([]time.Time, diskCount)

   *
   * <p>This method is intended to help with usages of type parameters that have {@linkplain
   * ParametricNullness parametric nullness}. Sometimes, code may receive a null {@code T} but store
   * a "null sentinel" to take its place. When the time comes to convert it back to a {@code T} to
   * return to a caller, the code needs to a way to return {@code null} from a method that returns
   * "plain {@code T}." This API provides that.
   */

        // Assert
        assertEquals(0x00000000, actual);
    }

    @ParameterizedTest
    @ValueSource(ints = { -1, 1, 0x00FFFF00, 0x0BADF00D })
    @DisplayName("Invalid or unknown DOS codes return not-found sentinel (-1)")
    void unknownCodesReturnMinusOne(int dosCode) {
        // Act
        int actual = findNtStatusOrMinusOne(dosCode);

        // Assert
        assertEquals(-1, actual);
    }

    @Test

// The zero Value for LruList is an empty list ready to use.
type LruList[K comparable, V any] struct {
	root Entry[K, V] // sentinel list element, only &root, root.prev, and root.next are used
	len  int         // current list Length excluding (this) sentinel element
}

// Init initializes or clears list l.
func (l *LruList[K, V]) Init() *LruList[K, V] {
	l.root.next = &l.root
	l.root.prev = &l.root

        // Stop the thread by sending n = -1
        synchronized (w) {
            w.write(new byte[0], -1, out);
        }

        w.join(2000);
        assertFalse(w.isAlive(), "WriterThread should stop after -1 sentinel");
    }

    @Test
    @DisplayName("WriterThread surfaces SmbException via checkException")
    void writerThread_propagates_exception() throws Exception {
        // Arrange

    static final long TTL = Config.getLong("jcifs.smb1.smb.client.dfs.ttl", 300);
    static final boolean DISABLED = Config.getBoolean("jcifs.smb1.smb.client.dfs.disabled", false);

    /**
     * Sentinel cache entry indicating a negative cache result
     */
    protected static CacheEntry FALSE_ENTRY = new Dfs.CacheEntry(0L);

    /**
     * Cache of trusted domains for DFS resolution
     */

   * or empty headers if there were none that followed.
   *
   * If the response body was closed prematurely or failed with an error, this will be the sentinel
   * value [TRAILERS_RESPONSE_BODY_TRUNCATED]. In that case attempts to read the trailers should not
   * return the value but instead throw an exception.
   */
  private var trailers: Headers? = null

			return &buf
		},
	}

	direntNamePool = bpool.Pool[*[]byte]{
		New: func() *[]byte {
			buf := make([]byte, blockSize)
			return &buf
		},
	}
)

// unexpectedFileMode is a sentinel (and bogus) os.FileMode
// value used to represent a syscall.DT_UNKNOWN Dirent.Type.
const unexpectedFileMode os.FileMode = os.ModeNamedPipe | os.ModeSocket | os.ModeDevice

   *
   * @param method defaults to "GET" if [body] is null, and "POST" otherwise.
   */
  constructor(
    url: HttpUrl,
    headers: Headers = headersOf(),
    // '\u0000' is a sentinel value that'll choose based on what the body is:
    method: String = "\u0000",
    body: RequestBody? = null,
  ) : this(
    Builder()
      .url(url)
      .headers(headers)
      .method(
        when {