values := url.Values{}
	values.Set("client_id", clientID)
	values.Set("client_secret", clientSecret)
	values.Set("grant_type", "client_credentials")

	req, err := http.NewRequest(http.MethodPost, k.oeConfig.TokenEndpoint, strings.NewReader(values.Encode()))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := k.client.Do(req)

		query := url.Values{}
		for key, value := range testCase.queryParams {
			query.Set(key, value)
		}
		// Create a request to use.
		req, err := http.NewRequest(http.MethodGet, "http://host/a/b?"+query.Encode(), nil)
		if err != nil {
			t.Errorf("(%d) failed to create http.Request, got %v", i, err)
		}
		if testCase.expected != ErrNone {

	}
	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,
		}
	}

	part, e := writer.CreateFormFile("file", filename)
	if e != nil {
		return "", e
	}

	if _, e = part.Write(payload); e != nil {
		return "", e
	}
	writer.Close()

	r, e := http.NewRequest(http.MethodPost, reqURL, &body)
	if e != nil {
		return "", e
	}
	r.Header.Add("Content-Type", writer.FormDataContentType())

	return c.submitPost(r)
}

}

func parseDiscoveryDoc(u *xnet.URL, transport http.RoundTripper, closeRespFn func(io.ReadCloser)) (DiscoveryDoc, error) {
	d := DiscoveryDoc{}
	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
	if err != nil {
		return d, err
	}
	clnt := http.Client{
		Transport: transport,
	}
	resp, err := clnt.Do(req)
	if err != nil {
		return d, err
	}

	data, err := json.Marshal(event.Log{EventName: eventData.EventName, Key: key, Records: []event.Event{eventData}})
	if err != nil {
		return err
	}

	req, err := http.NewRequest(http.MethodPost, target.args.Endpoint.String(), bytes.NewReader(data))
	if err != nil {
		return err
	}

	// Verify if the authToken already contains
	// <Key> <Token> like format, if this is

	}

	for i, testCase := range testCases {
		// creating an input HTTP request.
		// Only the headers are relevant for this particular test.
		inputReq, err := http.NewRequest(http.MethodGet, "http://example.com", nil)
		if err != nil {
			t.Fatalf("Error initializing input HTTP request: %v", err)
		}
		if testCase.inputQueryKey != "" {
			q := inputReq.URL.Query()

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)
	}

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.

	Transport   http.RoundTripper     `json:"-"`
	CloseRespFn func(r io.ReadCloser) `json:"-"`
}

// Validate - validate opa configuration params.
func (a *Args) Validate() error {
	req, err := http.NewRequest(http.MethodPost, a.URL.String(), bytes.NewReader([]byte("")))
	if err != nil {
		return err
	}

	req.Header.Set("Content-Type", "application/json")
	if a.AuthToken != "" {