} catch (UnsupportedOperationException e) {
      return;
    }

    Set<Entry<K, V>> entrySet = map.entrySet();
    if (supportsRemove) {
      try {
        entrySet.retainAll(null);
        // Returning successfully is not ideal, but tolerated.
      } catch (NullPointerException tolerated) {
      }
    } else {
      try {
        entrySet.retainAll(null);

			},
			nil, nil,
		},
		// Checks if wrapped context cancellation errors are grouped as one.
		{canceledErrs, nil, context.Canceled},
	}
	// Validates list of all the testcases for returning valid errors.
	for i, testCase := range testCases {
		gotErr := reduceReadQuorumErrs(t.Context(), testCase.errs, testCase.ignoredErrs, 5)
		if gotErr != testCase.err {

    public Object evaluate(final String template, final Map<String, Object> paramMap) {
        if (StringUtil.isBlank(template)) {
            if (logger.isDebugEnabled()) {
                logger.debug("Template is blank, returning null");
            }
            return null;
        }

        final Map<String, Object> safeParamMap = paramMap != null ? paramMap : Collections.emptyMap();

        } finally {
            // Clean up system property
            System.clearProperty(Constants.FESS_CONFIG_PREFIX + testKey);
        }
    }

    // Test property filter returning null simulation
    @Test
    public void test_get_filterReturnsNull() {
        // The filter.null property is configured to simulate null filter behavior
        try {
            fessConfig.get("filter.null");

 *       This method is used to clear and check for thread assertion failures.
 *   <li>All threads generated must be joined inside each test case method (or {@code fail} to do
 *       so) before returning from the method. The {@code joinPool} method can be used to do this
 *       when using Executors.
 * </ol>
 *
 * <p><b>Other notes</b>
 *
 * <ul>

また、`from starlette.responses import JSONResponse` も利用できます。

**FastAPI** は開発者の利便性のために `fastapi.responses` という `starlette.responses` と同じものを提供しています。しかし、利用可能なレスポンスのほとんどはStarletteから直接提供されます。

///

## カスタム `Response` を返す { #returning-a-custom-response }

上記の例では必要な部分を全て示していますが、あまり便利ではありません。`item` を直接返すことができるし、**FastAPI** はそれを `dict` に変換して `JSONResponse` に含めてくれるなど。すべて、デフォルトの動作です。

では、これを使ってカスタムレスポンスをどう返すか見てみましょう。

	case aggFnMax:
		if !e.aggregate.seen {
			// No rows were seen by MAX
			return FromNull(), nil
		}
		return e.aggregate.runningMax, nil

	case aggFnSum:
		// TODO: check if returning 0 when no rows were seen
		// by SUM is expected behavior.
		return e.aggregate.runningSum, nil

	default:
		// TODO:
	}

	return nil, errInvalidAggregation

   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_nullCollectionReferenceEmptySubject() {
    try {
      collection.retainAll(null);
      // Returning successfully is not ideal, but tolerated.
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)

   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_nullCollectionReferenceEmptySubject() {
    try {
      collection.retainAll(null);
      // Returning successfully is not ideal, but tolerated.
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)

   *
   * The returned client installs a default event listener that gathers debug information. This will
   * be logged if the test fails.
   *
   * This client is also configured to be slightly more deterministic, returning a single IP
   * address for all hosts, regardless of the actual number of IP addresses reported by DNS.
   */
  fun newClient(): OkHttpClient {
    var client = testClient
    if (client == null) {
      client =