func (h *SingleHandler[Req, Resp]) NewResponse() Resp {
	return h.newResp()
}

// NewRequest creates a new request.
// Handlers can use this to create a reusable request.
// The request may be reused, so caller should clear any fields.
func (h *SingleHandler[Req, Resp]) NewRequest() Req {
	return h.newReq()
}

// Register a handler for a Req -> Resp roundtrip.

func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

// Copied from http.NewRequest but implemented to ensure we reuse `url.URL` instance.
func (c *Client) newRequest(ctx context.Context, u url.URL, body io.Reader) (*http.Request, error) {
	rc, ok := body.(io.ReadCloser)
	if !ok && body != nil {
		rc = io.NopCloser(body)
	}

	}
	uaAppend(")", "")

	return strings.Join(userAgentParts, "")
}

func downloadReleaseURL(u *url.URL, timeout time.Duration, mode string) (content string, err error) {
	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
	if err != nil {
		return content, AdminError{
			Code:       AdminUpdateUnexpectedFailure,
			Message:    err.Error(),
			StatusCode: http.StatusInternalServerError,
		}
	}

	var jsonScopeInfo bytes.Buffer
	err := json.NewEncoder(&jsonScopeInfo).Encode(scope)
	if err != nil {
		return fmt.Errorf("cannot serialize scope %+v", *scope)
	}
	req, err := http.NewRequest(http.MethodPut, c.baseURL.String()+"/"+scope.Name, &jsonScopeInfo)
	if err != nil {
		return err
	}
	defer req.Body.Close()

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return err
	}

	}
	writer.Write([]byte("hello world"))
	// Close before creating the new request.
	w.Close()

	// Set the body equal to the created policy.
	reader := bytes.NewReader(buf.Bytes())

	req, err := http.NewRequest(http.MethodPost, makeTestTargetURL(endPoint, bucketName, "", nil), reader)
	if err != nil {
		return nil, err
	}

	// Set form content-type.
	req.Header.Set("Content-Type", w.FormDataContentType())

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).