field.isAccessible = true
      val value = field.get(instance)
      return if (!fieldType.isInstance(value)) null else fieldType.cast(value)
    } catch (_: NoSuchFieldException) {
    }

    c = c.superclass
  }

  // Didn't find the field we wanted. As a last gasp attempt,
  // try to find the value on a delegate.
  if (fieldName != "delegate") {

    }
    return total;
  }

  private long aggregateBelowRange(Aggregate aggr, @Nullable AvlNode<E> node) {
    if (node == null) {
      return 0;
    }
    // The cast is safe because we call this method only if hasLowerBound().
    int cmp =
        comparator()
            .compare(uncheckedCastNullableTToT(range.getLowerEndpoint()), node.getElement());
    if (cmp < 0) {

 *       to <i>some</i> degree to make this unlikely. (Without this condition, a function that
 *       always returns zero could be called a hash function. It is not.)
 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *

 *       to <i>some</i> degree to make this unlikely. (Without this condition, a function that
 *       always returns zero could be called a hash function. It is not.)
 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *

	// just ignore these.

	return nil
}

func readDirectoryEnd(r io.ReaderAt, size int64) (dir *directoryEnd, baseOffset int64, err error) {
	// look for directoryEndSignature in the last 1k, then in the last 65k
	var buf []byte
	var directoryEndOffset int64
	for i, bLen := range []int64{1024, 65 * 1024} {
		if bLen > size {
			bLen = size
		}
		buf = make([]byte, int(bLen))

  private transient int[] nextInBucketVToK;

  /** The "entry" of the first element in insertion order. */
  private transient int firstInInsertionOrder;

  /** The "entry" of the last element in insertion order. */
  private transient int lastInInsertionOrder;

  /** Maps an "entry" to the "entry" that precedes it in insertion order. */
  private transient int[] prevInInsertionOrder;

				loi.Prefixes = append(loi.Prefixes, obj.Name)
			}
		} else {
			loi.Objects = append(loi.Objects, obj)
		}
	}
	if loi.IsTruncated {
		last := objects[len(objects)-1]
		loi.NextMarker = opts.encodeMarker(last.Name)
		loi.NextVersionIDMarker = last.VersionID
	}
	return loi, nil
}

func maxKeysPlusOne(maxKeys int, addOne bool) int {
	if maxKeys < 0 || maxKeys > maxObjectList {

// Write object header
func setObjectHeaders(ctx context.Context, w http.ResponseWriter, objInfo ObjectInfo, rs *HTTPRangeSpec, opts ObjectOptions) (err error) {
	// set common headers
	setCommonHeaders(w)

	// Set last modified time.
	lastModified := objInfo.ModTime.UTC().Format(http.TimeFormat)
	w.Header().Set(xhttp.LastModified, lastModified)

	// Set Etag if available.
	if objInfo.ETag != "" {

	}
	if locksHeld > ReadLock {
		l.lockMap[args.Resources[0]] = locksHeld - ReadLock // Remove one of the read locks held
	} else {
		delete(l.lockMap, args.Resources[0]) // Remove the (last) read lock
	}
	return reply, nil
}

func (l *lockServer) Refresh(args *LockArgs) (reply bool, err error) {
	if d := atomic.LoadInt64(&l.responseDelay); d != 0 {
		time.Sleep(time.Duration(d))
	}

与其他响应类型相比，接受不同的参数集进行实例化：

* `path` - 要流式传输的文件的文件路径。
* `headers` - 任何自定义响应头，传入字典类型。
* `media_type` - 给出媒体类型的字符串。如果未设置，则文件名或路径将用于推断媒体类型。
* `filename` - 如果给出，它将包含在响应的 `Content-Disposition` 中。

文件响应将包含适当的 `Content-Length`，`Last-Modified` 和 `ETag` 的响应头。

{* ../../docs_src/custom_response/tutorial009.py hl[2,10] *}

## 额外文档