if userDefined["content-type"] == "" {
		userDefined["content-type"] = mimedb.TypeByExtension(path.Ext(object))
	}

	// if storageClass is standard no need to save it as part of metadata.
	if userDefined[xhttp.AmzStorageClass] == storageclass.STANDARD {
		delete(userDefined, xhttp.AmzStorageClass)
	}

	if opts.WantChecksum != nil && opts.WantChecksum.Type.IsSet() {

	if userDefined["content-type"] == "" {
		userDefined["content-type"] = mimedb.TypeByExtension(path.Ext(object))
	}

	// if storageClass is standard no need to save it as part of metadata.
	if userDefined[xhttp.AmzStorageClass] == storageclass.STANDARD {
		delete(userDefined, xhttp.AmzStorageClass)
	}

	// Fill all the necessary metadata.
	// Update `xl.meta` content on each disks.

		// AWS S3 silently drops checksums on range requests.
		cs, _ := objInfo.decryptChecksums(opts.PartNumber, r.Header)
		hash.AddChecksumHeader(w, cs)
	}

	// Set standard object headers.
	if err = setObjectHeaders(ctx, w, objInfo, rs, opts); err != nil {
		writeErrorResponseHeadersOnly(w, toAPIError(ctx, err))
		return
	}

	// Set Parts Count Header