* Den `request`.
* Eine Funktion `call_next`, die den `request` als Parameter erhält.
    * Diese Funktion gibt den `request` an die entsprechende *Pfadoperation* weiter.
    * Dann gibt es die von der entsprechenden *Pfadoperation* generierte `response` zurück.
* Sie können die `response` dann weiter modifizieren, bevor Sie sie zurückgeben.

```Python hl_lines="8-9  11  14"
{!../../docs_src/middleware/tutorial001.py!}
```

/// tip | "Tipp"

	// if object upload fails stop the test.
	if err != nil {
		t.Fatalf("Error uploading object: <ERROR> %v", err)
	}

	// initialize httptest Recorder, this records any mutations to response writer inside the handler.
	rec := httptest.NewRecorder()
	// construct HTTP request for DELETE bucket.

    stream = io.BytesIO(b"data")
    file = UploadFile(filename="file", file=stream, size=4)
    assert await file.read() == b"data"
    assert file.size == 4
    await file.write(b" and more data!")
    assert await file.read() == b""
    assert file.size == 19
    await file.seek(0)
    assert await file.read() == b"data and more data!"

func ExampleWriter_ReadFrom() {
	var buf bytes.Buffer
	writer := bufio.NewWriter(&buf)

	data := "Hello, world!\nThis is a ReadFrom example."
	reader := strings.NewReader(data)

	n, err := writer.ReadFrom(reader)
	if err != nil {
		fmt.Println("ReadFrom Error:", err)
		return
	}

	if err = writer.Flush(); err != nil {
		fmt.Println("Flush Error:", err)

):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None:
            await websocket.send_text(f"Query parameter q is: {q}")

    cookie_or_token: str = Depends(get_cookie_or_token),
):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None:
            await websocket.send_text(f"Query parameter q is: {q}")

):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None:
            await websocket.send_text(f"Query parameter q is: {q}")

):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(
            f"Session cookie or query token value is: {cookie_or_token}"
        )
        if q is not None:
            await websocket.send_text(f"Query parameter q is: {q}")

	if !corruptedMultipart {
		var writer io.Writer
		var err error
		if noFilename {
			writer, err = w.CreateFormField("file")
		} else {
			writer, err = w.CreateFormFile("file", "upload.txt")
		}
		if err != nil {
			// return nil, err
			return nil, err
		}
		writer.Write(objData)
		// Close before creating the new request.
		w.Close()
	}

        if (!artifactFile.getParentFile().exists()) {
            artifactFile.getParentFile().mkdirs();
        }
        try (Writer writer = new OutputStreamWriter(new FileOutputStream(artifactFile), StandardCharsets.ISO_8859_1)) {
            writer.write(artifact.getId());
        }

        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(artifact.getId().getBytes());