if err != nil {
		t.Fatal(err)
	}

	lkClient := newlockRESTClient(endpoint)
	if lkClient.IsOnline() {
		t.Fatalf("unexpected result. connection was online")
	}

	// Attempt all calls.
	_, err = lkClient.RLock(context.Background(), dsync.LockArgs{})
	if err == nil {
		t.Fatal("Expected for Rlock to fail")
	}

But that file doesn't exist, our dependencies are in a file at `app/dependencies.py`.

Remember how our app/file structure looks like:

<img src="/img/tutorial/bigger-applications/package.svg">

---

The two dots `..`, like in:

```Python
from ..dependencies import get_token_header
```

mean:

<div class="termy">

```console
$ OPENAPI_URL= uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Then if you go to the URLs at `/openapi.json`, `/docs`, or `/redoc` you will just get a `404 Not Found` error like:

```JSON
{
    "detail": "Not Found"
}

If you are curious about how the raw OpenAPI schema looks like, FastAPI automatically generates a JSON (schema) with the descriptions of all your API.

You can see it directly at: <a href="http://127.0.0.1:8000/openapi.json" class="external-link" target="_blank">http://127.0.0.1:8000/openapi.json</a>.

It will show a JSON starting with something like:

```JSON
{
    "openapi": "3.1.0",
    "info": {

For example, you could use it to read and verify passwords generated by another system (like Django) but hash any new passwords with a different algorithm like Bcrypt.

And be compatible with all of them at the same time.

///

Create a utility function to hash a password coming from the user.

They're also concrete: each URL identifies a specific path (like `/square/okhttp`) and query (like `?q=sharks&lang=en`). Each webserver hosts many URLs.

### [Addresses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-address/)

Addresses specify a webserver (like `github.com`) and all of the **static** configuration necessary to connect to that server: the port number, HTTPS settings, and preferred network protocols (like HTTP/2).

          "hide": false,
          "instant": true,
          "legendFormat": ".",
          "range": false,
          "refId": "B"
        }
      ],
      "title": "Total Online/Offline Drives",
      "type": "gauge"
    },
    {
      "datasource": {
        "type": "prometheus",
        "uid": "${DS_PROMETHEUS}"
      },
      "fieldConfig": {
        "defaults": {

                                            key="labels.boost_document_rule_sort_order"/></label>
                                    <div class="form-inline col-sm-9">
                                        <la:errors property="sortOrder"/>
                                        <input type="number" name="sortOrder" id="sortOrder"

                                            key="labels.key_match_size"/></label>
                                    <div class="form-inline col-sm-9">
                                        <la:errors property="maxSize"/>
                                        <input type="number" name="maxSize" id="maxSize"

* 可获取上传文件的元数据；
* 自带 <a href="https://docs.python.org/zh-cn/3/glossary.html#term-file-like-object" class="external-link" target="_blank">file-like</a> `async` 接口；
* 暴露的 Python <a href="https://docs.python.org/zh-cn/3/library/tempfile.html#tempfile.SpooledTemporaryFile" class="external-link" target="_blank">`SpooledTemporaryFile`</a> 对象，可直接传递给其他预期「file-like」对象的库。

### `UploadFile`

`UploadFile` 的属性如下：