Download a file, print its headers, and print its response body as a string.

The `string()` method on response body is convenient and efficient for small documents. But if the response body is large (greater than 1 MiB), avoid `string()` because it will load the entire document into memory. In that case, prefer to process the body as a stream.

=== ":material-language-kotlin: Kotlin"
    ```kotlin

   * proceed to read the response body with [Response.body]. The response is still live until its
   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *
   * Note that transport-layer success (receiving a HTTP response code, headers and body) does not

from fastapi import APIRouter, Body

router = APIRouter()


@router.post("/compute/")
def compute(a: int = Body(), b: str = Body()):

}

func mainHandler(w http.ResponseWriter, r *http.Request) {
	body, err := io.ReadAll(r.Body)
	defer r.Body.Close()
	if err != nil {
		log.Printf("Error reading request body: %v", err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	log.Printf(">>> %s %s\n", r.Method, r.URL.Path)
	var out bytes.Buffer
	json.Indent(&out, body, "", "    ")
	log.Printf("%s\n", out.String())

	w.WriteHeader(http.StatusOK)

    val same = brotliInterceptor.decompress(response)

    val responseString = same.body.string()
    assertThat(responseString).isEmpty()
  }

  private fun response(
    url: String,
    bodyHex: ByteString,
    fn: Response.Builder.() -> Unit = {},
  ): Response =
    Response
      .Builder()
      .body(bodyHex.toResponseBody("text/plain".toMediaType()))
      .code(200)
      .message("OK")

)

// DrainBody close non nil response with any response Body.
// convenient wrapper to drain any remaining data on response body.
//
// Subsequently this allows golang http RoundTripper
// to reuse the same connection for future requests.
func DrainBody(respBody io.ReadCloser) {
	// Callers should close resp.Body when done reading from it.
	// If resp.Body is not closed, the Client's underlying RoundTripper

    /**
     * Checks if this response has a response body.
     *
     * @return true if the response has a body (either as bytes or file), false otherwise
     */
    public boolean hasResponseBody() {
        return responseBodyBytes != null || responseBodyFile != null;
    }

    /**
     * Gets the response body as an InputStream.
     * If the response body is stored as bytes, returns a ByteArrayInputStream.

  fun successfulCallEventSequence() {
    server.enqueue(MockResponse(body = "abc"))
    val call =
      client.newCall(
        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    val response = call.execute()
    assertThat(response.code).isEqualTo(200)
    assertThat(response.body.string()).isEqualTo("abc")
    response.body.close()
    assertThat(listener.recordedEventTypes()).containsExactly(

    if (!response.promisesBody()) {
      return response
    }
    val body = response.body
    val encoding = response.header("Content-Encoding") ?: return response

    val algorithm = lookupDecompressor(encoding) ?: return response

    val decompressedSource = algorithm.decompress(body.source()).buffer()

    return response
      .newBuilder()
      .removeHeader("Content-Encoding")

/// warning

You can declare multiple `File` and `Form` parameters in a *path operation*, but you can't also declare `Body` fields that you expect to receive as JSON, as the request will have the body encoded using `multipart/form-data` instead of `application/json`.

This is not a limitation of **FastAPI**, it's part of the HTTP protocol.

///

## Recap { #recap }