//
// If the current file is sparse and r is an io.ReadSeeker,
// then readFrom uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are all NULs.
// This always reads the last byte to ensure r is the right size.
//
// TODO(dsnet): Re-export this when adding sparse file support.
// See https://golang.org/issue/22735

# `Response` class

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```

     * <p>To avoid races between threads doing release and acquire, we transition to the final state
     * in two steps. One thread will successfully CAS from RUNNING to COMPLETING, that thread will
     * then set the result of the computation, and only then transition to COMPLETED, CANCELLED, or
     * INTERRUPTED.
     *
     * <p>We don't use the integer argument passed between acquire methods so we pass around a -1
     * everywhere.
     */

# Docker on Windows has difficulty using volumes other than C:\, when it comes
# to setting up up volume mappings.
# Thus, the drive letter is replaced with the passed prefix.
# If no prefix is passed, by default, it's replaced with C:\, in case it's
# something else (ex. T:), which is a volume used in internal CI.
function replace_drive_letter_with_prefix () {
  local path_prefix
  if [[ -z "$2" ]]; then
    path_prefix="C:"
  else
    path_prefix="$2"

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

## Import `File` and `Form` { #import-file-and-form }

{* ../../docs_src/request_forms_and_files/tutorial001_an_py39.py hl[3] *}

# Advanced Middleware { #advanced-middleware }

In the main tutorial you read how to add [Custom Middleware](../tutorial/middleware.md){.internal-link target=_blank} to your application.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares { #adding-asgi-middlewares }

     * <ul>
     *   <li>
     *     If no module name, then the default directory is
     *     <code>src/{@linkplain #scope() scope}/{@linkplain #language() language}</code>.
     *   </li><li>
     *     If a module name is present, then the default directory is
     *     <code>src/{@linkplain #module() module}/{@linkplain #scope() scope}/{@linkplain #language() language}</code>.

        lenient().when(tree.acquire()).thenReturn(tree);
        lenient().when(tree.getConfig()).thenReturn(config);
        lenient().when(config.getListCount()).thenReturn(10);
        lenient().when(config.getListSize()).thenReturn(4096);

        lenient().when(parent.getLocator()).thenReturn(locator);
        lenient().when(locator.getUNCPath()).thenReturn("\\\\SERVER\\Share\\dir\\"); // ends with \\

 *
 * Do not confuse this class with the misnamed `HttpURLConnection`, which isn't so much a connection
 * as a single request/response exchange.
 *
 * ## Modern TLS
 *
 * There are trade-offs when selecting which options to include when negotiating a secure connection
 * to a remote host. Newer TLS options are quite useful:
 *
 *  * Server Name Indication (SNI) enables one IP address to negotiate secure connections for

  quay.io/minio/minio server /data --console-address ":9001"
```

The command creates a new local directory `~/minio/data` in your user home directory. It then starts the MinIO container with the `-v` argument to map the local path (`~/minio/data`) to the specified virtual container directory (`/data`). When MinIO writes data to `/data`, that data is actually written to the local path `~/minio/data` where it can persist between container restarts.

### Windows