mac.init(SHA1_KEY);
    mac.update("hello".getBytes(UTF_8));
    mac.update("world".getBytes(UTF_8));

    assertEquals(
        HashCode.fromBytes(mac.doFinal()),
        Hashing.hmacSha1(SHA1_KEY)
            .newHasher()
            .putString("hello", UTF_8)
            .putString("world", UTF_8)
            .hash());
  }

  public void testMultipleUpdatesDoFinal() throws Exception {

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

آرگومان دوم <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> مقدار پیش‌فرضیه که برمی‌گردونه.

اگه ندی، به‌صورت پیش‌فرض `None` هست، اینجا ما `"World"` رو به‌عنوان مقدار پیش‌فرض گذاشتیم.

///

	Name4        string `gorm:"uniqueIndex"`
	Name5        int64  `gorm:"index:,class:FULLTEXT,comment:hello \\, world,where:age > 10"`
	Name6        int64  `gorm:"index:profile,comment:hello \\, world,where:age > 10"`
	Age          int64  `gorm:"index:profile,expression:ABS(age),option:WITH PARSER parser_name"`
	OID          int64  `gorm:"index:idx_id;index:idx_oid,unique"`

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///

例如，你可以建立一個名為 `main.py` 的檔案，其中包含以下內容：

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

第二個參數是 <a href="https://docs.python.org/zh-tw/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的預設回傳值。

如果沒有提供，預設值為 `None`，這裡我們提供 `"World"` 作為預設值。

///

然後你可以呼叫這個 Python 程式：

//// tab | Linux, macOS, Windows Bash

```txt
Hello, World from Flask!
```

Y si vas a <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> verás el response de FastAPI:

```JSON
{
    "message": "Hello World"
}

  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");
    webSocket.send(ByteString.decodeHex("deadbeef"));
    webSocket.close(1000, "Goodbye, World!");
  }

  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("MESSAGE: " + text);
  }

```txt
Hello, World from Flask!
```

Eğer <a href="http://localhost:8000/v2/" class="external-link" target="_blank">http://localhost:8000/v2/</a> adresine giderseniz, FastAPI'dan gelen yanıtı göreceksiniz:

```JSON
{
    "message": "Hello World"
}

        Did you *actually* encounter the need for this feature in a real-world scenario, or is it
        just a feature that seems like a sensible addition to Guava?


        Before new features get added to Guava, we really want to be sure that it's for a use case
        that actually comes up in the real world. We want to hear the real-world use case so the

```txt
Hello, World from Flask!
```

And if you go to <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> you will see the response from FastAPI:

```JSON
{
    "message": "Hello World"
}