// We must not use the http.Header().Set method here because some (broken)
	// clients expect the x-amz-copy-source-version-id header key to be literally
	// "x-amz-copy-source-version-id"- not in canonicalized form, preserve it.
	if srcOpts.VersionID != "" {
		w.Header()[strings.ToLower(xhttp.AmzCopySourceVersionID)] = []string{srcOpts.VersionID}
	}

	// Write success response.