Dummy sneaky = map.putIfAbsent(sample, Dummy.VALUE);
        if (sneaky == null) {
          return sample;
        } else {
          /* Someone beat us to it! Trying again...
           *
           * Technically this loop not guaranteed to terminate, so theoretically (extremely
           * unlikely) this thread might starve, but even then, there is always going to be another

	if err != nil {
		errRet := fmt.Errorf("LDAP auth failed for DN %s: %w", lookupResult.ActualDN, err)
		return nil, nil, errRet
	}

	// Bind to the lookup user account again to perform group search.
	if err = l.LDAP.LookupBind(conn); err != nil {
		return nil, nil, err
	}

	// User groups lookup.
	groups, err := l.LDAP.SearchForUserGroups(conn, username, lookupResult.ActualDN)

## 標題 { #headings }

//// tab | 測試

### 開發網頁應用程式 - 教學 { #develop-a-webapp-a-tutorial }

Hello.

### 型別提示與註解 { #type-hints-and-annotations }

Hello again.

### 超類與子類別 { #super-and-subclasses }

Hello again.

////

//// tab | 資訊

標題唯一的硬性規則是保留花括號中的雜湊片段不變，以確保連結不會失效。

請見 `scripts/translate.py` 中通用提示的 `### Headings` 小節。

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;
    AtomicInteger callCount = new AtomicInteger();

        // Commit
        callback.commit();

        assertEquals(1, commitCount.get());
        assertEquals(3L, documentsBeforeCommit.get());

        // Store more and commit again
        callback.store(params, data);
        callback.store(params, data);

        assertEquals(5L, callback.getDocumentSize());

        callback.commit();

        assertEquals(2, commitCount.get());

        assertNotNull(hash);

        // Modify returned hash
        if (hash.length > 0) {
            hash[0] = (byte) 0xFF;
        }

        // Get hash again - should be unmodified
        byte[] hash2 = transport.getPreauthIntegrityHash();
        assertNotNull(hash2);

        // If original has data, verify it wasn't modified

        // Test engineReset()
        HMACT64 hmac = new HMACT64(TEST_KEY);
        hmac.engineUpdate(TEST_DATA, 0, TEST_DATA.length);
        hmac.engineReset();
        // After reset, should be able to digest again
        byte[] result = hmac.engineDigest();
        assertNotNull(result);
    }

    @Test
    void testEngineGetDigestLength() {
        // Test engineGetDigestLength()

    checkThreadPoolName(thread2, 2);
    assertThat(thread2.getName().substring(0, thread.getName().lastIndexOf('-')))
        .isEqualTo(thread.getName().substring(0, thread.getName().lastIndexOf('-')));

    // Building again should give us a different pool ID.
    ThreadFactory threadFactory2 = builder.build();
    Thread thread3 = threadFactory2.newThread(monitoredRunnable);
    checkThreadPoolName(thread3, 1);

   * {@code maximumSize / concurrencyLevel}.
   *
   * <p>When eviction is necessary, the cache evicts entries that are less likely to be used again.
   * For example, the cache may evict an entry because it hasn't been used recently or very often.
   *
   * <p>If {@code maximumSize} is zero, elements will be evicted immediately after being loaded into

            the dependency is declared again for the rest of the request (for example
            if the dependency is needed by several dependencies), the value will be
            re-used for the rest of the request.

            Set `use_cache` to `False` to disable this behavior and ensure the
            dependency is called again (if declared more than once) in the same request.