* range set.
   *
   * @throws NoSuchElementException if this range set is {@linkplain #isEmpty() empty}
   */
  Range<C> span();

  // Views

  /**
   * Returns a view of the {@linkplain Range#isConnected disconnected} ranges that make up this
   * range set. The returned set may be empty. The iterators returned by its {@link

      return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

      return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? immutableEntry(range, values.get(index)) : null;
    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);

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

因為 OAuth2 會以「form data」傳送 `username` 與 `password`。

///

用以下指令執行範例：

<div class="termy">

```console
$ fastapi dev

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

</div>

## 檢查 { #check-it }

開啟互動式文件：[http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs)。

你會看到類似這樣：

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

这是因为 **OAuth2** 使用“表单数据”来发送 `username` 和 `password`。

///

用下面的命令运行示例：

<div class="termy">

```console
$ fastapi dev

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

</div>

## 查看 { #check-it }

打开交互式文档：[http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs)。

你会看到类似这样的界面：

다음으로 환경 변수를 통해 구성을 전달하면서 서버를 실행합니다. 예를 들어 다음처럼 `ADMIN_EMAIL`과 `APP_NAME`을 설정할 수 있습니다:

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

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

</div>

/// tip | 팁

하나의 명령에 여러 env var를 설정하려면 공백으로 구분하고, 모두 명령 앞에 두세요.

///

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

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

</div>

/// tip

					</la:link>
					<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbar" aria-controls="navbar"
						aria-expanded="false" aria-label="Toggle navigation">
						<span class="navbar-toggler-icon"></span>
					</button>
					<div class="collapse navbar-collapse" id="navbar">
						<div class="me-auto"></div>
						<ul class="nav navbar-nav">
							<c:if test="${eoled}">

echo "Hello universe"
```

...and a console code example...

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:solid">main.py</u>
<span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting server
        Searching for package file structure
```

...and another console code example...

```console
// Create a directory "Code"
$ mkdir code

     * <p>
     * The returned duration is calculated using {@link System#nanoTime()}
     * to ensure monotonic behavior. This duration represents the exact time
     * span between clock initialization and the current instant.
     *
     * @return the duration since clock initialization
     * @see #startInstant()
     * @see #instant()
     */
    public Duration elapsedTime() {