func (m *metacacheManager) initManager() {
	// Add a transient bucket.
	// Start saver when object layer is ready.
	go func() {
		objAPI := newObjectLayerFn()
		for objAPI == nil {
			time.Sleep(time.Second)
			objAPI = newObjectLayerFn()
		}

		t := time.NewTicker(time.Minute)
		defer t.Stop()

		var exit bool
		for !exit {
			select {
			case <-t.C:
			case <-GlobalContext.Done():
				exit = true

			if objLen == 0 {
				continue
			}

			// Various ranges to query - all are valid!
			rangeHdrs := []string{
				// Read first byte of object
				fmt.Sprintf("bytes=%d-%d", 0, 0),
				// Read second byte of object
				fmt.Sprintf("bytes=%d-%d", 1, 1),
				// Read last byte of object
				fmt.Sprintf("bytes=-%d", 1),
				// Read all but first byte of object
				"bytes=1-",
				// Read first half of object

                return 50;
            }
        });

        RescorerBuilder<?> result1 = ltrQueryRescorer.evaluate(params);
        assertNotNull(result1);

        // Second call without model name
        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            @Override
            public String getLtrModelName() {
                return "";
            }

     * simple approach would be for each caller CAS it from null to a Set populated with its
     * exception. But there's another race: If the first thread fails with an exception and a second
     * thread immediately fails with the same exception:
     *
     * Thread1: calls setException(), which returns true, context switch before it can CAS
     * seenExceptionsField to its exception
     *

        long total = requestsSent.get();
        if (total == 0)
            return 0.0;
        return (double) errors.get() / total;
    }

    /**
     * Get throughput in bytes per second
     *
     * @return throughput in bps
     */
    public long getThroughput() {
        long duration = System.currentTimeMillis() - establishedTime;
        if (duration == 0)
            return 0;

  /** The first exception encountered if any threadAssertXXX method fails. */
  private final AtomicReference<Throwable> threadFailure = new AtomicReference<>(null);

  /**
   * Records an exception so that it can be rethrown later in the test harness thread, triggering a
   * test case failure. Only the first failure is recorded; subsequent calls to this method from
   * within the same test have no effect.
   */

type scannerMetrics struct {
	// All fields must be accessed atomically and aligned.
	operations [scannerMetricLast]uint64
	latency    [scannerMetricLastRealtime]lockedLastMinuteLatency

	// actions records actions performed.
	actions        [lifecycle.ActionCount]uint64
	actionsLatency [lifecycle.ActionCount]lockedLastMinuteLatency

	// currentPaths contains (string,*currentPathTracker) for each disk processing.

 *
 * Regular lines contain fields separated by semicolons.
 *
 * The first element on each line is a single hex code point (like 0041) or a hex code point range
 * (like 0030..0039).
 *
 * The second element on each line is a mapping type, like `valid` or `mapped`.
 *
 * For lines that contain a mapping target, the next thing is a sequence of hex code points (like
 * 0031 2044 0034).
 *
 * All other data is ignored.

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

이 의존성은 선택적 쿼리 파라미터 `q`를 `str`로 선언하고, 그대로 반환합니다.

매우 단순한 예시(그다지 유용하진 않음)이지만, 하위 의존성이 어떻게 동작하는지에 집중하는 데 도움이 됩니다.

## 두 번째 의존성 "dependable"과 "dependant" { #second-dependency-dependable-and-dependant }

그다음, 또 다른 의존성 함수("dependable")를 만들 수 있는데, 이 함수는 동시에 자기 자신의 의존성도 선언합니다(그래서 "dependant"이기도 합니다):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

선언된 파라미터를 살펴보겠습니다:

你可以建立第一個相依項（"dependable"）如下：

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

它宣告了一個可選的查詢參數 `q`（型別為 `str`），然後直接回傳它。

這很簡單（不太實用），但有助於我們專注於子相依如何運作。

## 第二個相依，同時是 "dependable" 也是 "dependant" { #second-dependency-dependable-and-dependant }

接著你可以建立另一個相依函式（"dependable"），同時它也宣告了自己的相依（因此它同時也是 "dependant"）：

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

來看它所宣告的參數：