h := sha256.New()
	for i, meta := range metaArr {
		if !meta.IsValid() {
			continue
		}
		etagOnly := modTime.Equal(timeSentinel) && (etag != "" && etag == meta.Metadata["etag"])
		mtimeValid := meta.ModTime.Equal(modTime)
		if mtimeValid || etagOnly {
			fmt.Fprintf(h, "%v", meta.XLV1)
			for _, part := range meta.Parts {
				fmt.Fprintf(h, "part.%d", part.Number)
				fmt.Fprintf(h, "part.%d", part.Size)

		Bucket:                     o.Bucket,
		Name:                       o.Name,
		ModTime:                    o.ModTime,
		Size:                       o.Size,
		IsDir:                      o.IsDir,
		ETag:                       o.ETag,
		VersionID:                  o.VersionID,
		IsLatest:                   o.IsLatest,
		DeleteMarker:               o.DeleteMarker,
		TransitionedObject:         o.TransitionedObject,

        "fe012443-6ba9-4ef2-bb94-b729d2060c78/test123/testw3c.pdf/xl.meta": {"Versions":[{"Type":1,"V2Obj":{"ID":"aGEA/ZUOR4ueRIZsA...

```Python
q: Union[str, None] = Query(default=None)
```

... rend le paramètre optionnel, et est donc équivalent à :

```Python
q: Union[str, None] = None
```

Mais déclare explicitement `q` comme étant un paramètre de requête.

/// info

Gardez à l'esprit que la partie la plus importante pour rendre un paramètre optionnel est :

```Python
= None
```

ou :

```Python
= Query(None)
```

		Bucket:      bucket,
		Name:        object,
		Size:        r.Size(),
		IsLatest:    true,
		ContentType: string(mimeXML),
		NumVersions: 1,
		ETag:        etag,
		ModTime:     UTCNow(),
	}, opts)

		// as well as common modtime, if modtime is not possible
		// verify if it has common "etag" at least.
		if onlineMeta[i].IsValid() && onlineMeta[i].Erasure.Equal(fi.Erasure) {
			ok := onlineMeta[i].ModTime.Equal(modTime)
			if modTime.IsZero() || modTime.Equal(timeSentinel) {
				ok = etag != "" && etag == fi.Metadata["etag"]
			}
			if ok {
				continue
			}

			z.PartNumber, bts, err = msgp.ReadIntBytes(bts)
			if err != nil {
				err = msgp.WrapError(err, "PartNumber")
				return
			}
		case "ETag":
			z.ETag, bts, err = msgp.ReadStringBytes(bts)
			if err != nil {
				err = msgp.WrapError(err, "ETag")
				return
			}
		case "Size":
			z.Size, bts, err = msgp.ReadInt64Bytes(bts)
			if err != nil {
				err = msgp.WrapError(err, "Size")
				return

		if err != nil {
			t.Errorf("%s: <ERROR> %s", instanceType, err)
		}
		if calcPartInfo.ETag != expectedETaghex {
			t.Errorf("MD5 Mismatch")
		}
		completedParts.Parts = append(completedParts.Parts, CompletePart{
			PartNumber: i,
			ETag:       calcPartInfo.ETag,
		})
	}

    // Special case some of the weird HTTP Header names...
    ImmutableBiMap<String, String> specialCases =
        ImmutableBiMap.<String, String>builder()
            .put("CDN_LOOP", "CDN-Loop")
            .put("ETAG", "ETag")
            .put("SOURCE_MAP", "SourceMap")
            .put("SEC_CH_UA_WOW64", "Sec-CH-UA-WoW64")
            .put("SEC_WEBSOCKET_ACCEPT", "Sec-WebSocket-Accept")

		return
	}

	etag := getDecryptedETag(formValues, objInfo, false)

	// We must not use the http.Header().Set method here because some (broken)
	// clients expect the ETag header key to be literally "ETag" - not "Etag" (case-sensitive).
	// Therefore, we have to set the ETag directly as map entry.
	w.Header()[xhttp.ETag] = []string{`"` + etag + `"`}