To see how to achieve this parallelism in production see the section about [Deployment](deployment/index.md).

## `async` and `await` { #async-and-await }

		var fw fileWriter
		switch maker := v.maker.(type) {
		case makeReg:
			fw = &regFileWriter{w, maker.size}
			wantStr = maker.wantStr
		case makeSparse:
			if !validateSparseEntries(maker.sph, maker.size) {
				t.Fatalf("invalid sparse map: %v", maker.sph)
			}
			spd := invertSparseEntries(maker.sph, maker.size)
			fw = &regFileWriter{w, maker.makeReg.size}
			fw = &sparseFileWriter{fw, spd, 0}

	}
	return loi, nil
}

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

func (z *erasureServerPools) listObjectsGeneric(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int, v1 bool) (loi ListObjectsInfo, err error) {
	opts := listPathOptions{

        final List<StorageItem> items = new ArrayList<>();

        try {
            final ListObjectsV2Request.Builder requestBuilder =
                    ListObjectsV2Request.builder().bucket(bucket).delimiter("/").maxKeys(maxItems);

            if (StringUtil.isNotBlank(prefix)) {
                final String normalizedPrefix = prefix.endsWith("/") ? prefix : prefix + "/";
                requestBuilder.prefix(normalizedPrefix);

	ListObjects(ctx context.Context, bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error)
	ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (result ListObjectsV2Info, err error)
	ListObjectVersions(ctx context.Context, bucket, prefix, marker, versionMarker, delimiter string, maxKeys int) (result ListObjectVersionsInfo, err error)

  }

  // TODO(cpovirk): instead of skipping, use a smaller number of steps
  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {
    actsLikeIteratorHelper(Lists.newArrayList("A", "B", "C"));
  }

  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorAcceptsNullElements() {

 *
 * <h2>Prefer <a href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a> over Guava's caching
 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a
 * nearly drop-in replacement. Note that it is not available for Android or GWT/J2CL and that it may
 * have <a href="https://github.com/ben-manes/caffeine/wiki/Guava">different (usually better)

            }
        }
    ]
}
```
Note: This rule has an implicit zero NoncurrentDays, which makes the expiry of those 'extra' noncurrent versions immediate.

#### 3.2.b Automatic removal of all versions (MinIO only extension)

This is available only on MinIO as an extension to the Expiration feature. The following rule makes it possible to remove all versions of an object under 

    @app.post("/upload")
    async def upload(files: Annotated[list[bytes], File()]):
        # return something that makes order obvious
        return [b[0] for b in files]

    original_read = StarletteUploadFile.read

    async def patched_read(self: StarletteUploadFile, size: int = -1) -> bytes:
        # Make the FIRST file slower *deterministically*
        if self.filename == "slow.txt":
            await anyio.sleep(0.05)

}

// return URL for listing objects in the bucket with V1 legacy API.
func getListObjectsV1URL(endPoint, bucketName, prefix, maxKeys, encodingType string) string {
	queryValue := url.Values{}
	if maxKeys != "" {
		queryValue.Set("max-keys", maxKeys)
	}
	if encodingType != "" {
		queryValue.Set("encoding-type", encodingType)
	}
	return makeTestTargetURL(endPoint, bucketName, prefix, queryValue)