func newTestStreamingRequest(method, urlStr string, dataLength, chunkSize int64, body io.ReadSeeker) (*http.Request, error) {
	if method == "" {
		method = http.MethodPost
	}

	req, err := http.NewRequest(method, urlStr, nil)
	if err != nil {
		return nil, err
	}

	if body == nil {
		// this is added to avoid panic during io.ReadAll(req.Body).