if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Status, string(madmin.GroupEnabled))
	c.mustListObjects(ctx, uClient, bucket)

	// 6. Verify that group cannot be deleted with users.
	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:    group,
		IsRemove: true,
	})
	if err == nil {
		c.Fatalf("group was removed!")
	}

The cashier says something to the cook in the kitchen so they know they have to prepare your burgers (even though they are currently preparing the ones for the previous clients).

<img src="/img/async/concurrent-burgers/concurrent-burgers-03.png" class="illustration">

You pay. 💸

The cashier gives you the number of your turn.

    // Starting with an 8k buffer, double the size of each successive buffer. Smaller buffers
    // quadruple in size until they reach 8k, to minimize the number of small reads for longer
    // streams. Buffers are retained in a deque so that there's no copying between buffers while
    // reading and so all of the bytes in each new allocated buffer are available for reading from
    // the stream.

burgers = get_burgers(2)
```

---

, 🚥 👆 ⚙️ 🗃 👈 💬 👆 👈 👆 💪 🤙 ⚫️ ⏮️ `await`, 👆 💪 ✍ *➡ 🛠️ 🔢* 👈 ⚙️ ⚫️ ⏮️ `async def`, 💖:

```Python hl_lines="2-3"
@app.get('/burgers')
async def read_burgers():
    burgers = await get_burgers(2)
    return burgers
```

### 🌅 📡 ℹ

👆 💪 ✔️ 👀 👈 `await` 💪 🕴 ⚙️ 🔘 🔢 🔬 ⏮️ `async def`.

                _src = _src.deferred;
                int _name_buffers = _src.dec_ndr_long();
                _src.dec_ndr_long();
                int _name_bufferl = _src.dec_ndr_long();
                int _name_bufferi = _src.index;
                _src.advance(2 * _name_bufferl);

                if (name.buffer == null) {
                    if (_name_buffers < 0 || _name_buffers > 0xFFFF) throw new NdrException( NdrException.INVALID_CONFORMANCE );

                int _name_buffers = _src.dec_ndr_long();
                _src.dec_ndr_long();
                int _name_bufferl = _src.dec_ndr_long();
                int _name_bufferi = _src.index;
                _src.advance(2 * _name_bufferl);

                if ( this.name.buffer == null ) {
                    if ( _name_buffers < 0 || _name_buffers > 0xFFFF )

// to the default size.
// Calling b.Reset(b) (that is, resetting a [Reader] to itself) does nothing.
func (b *Reader) Reset(r io.Reader) {
	// If a Reader r is passed to NewReader, NewReader will return r.
	// Different layers of code may do that, and then later pass r
	// to Reset. Avoid infinite recursion in that case.
	if b == r {
		return
	}
	if b.buf == nil {
		b.buf = make([]byte, defaultBufSize)
	}
	b.reset(b.buf, r)
}

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

Dann sind Sie an der Reihe und Sie bestellen zwei sehr schmackhafte Burger für Ihren Schwarm und Sie. 🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

```Python hl_lines="1"
async def get_burgers(number: int):
    # Do some asynchronous stuff to create the burgers
    return burgers
```

...en vez de `def`:

```Python hl_lines="2"
# This is not asynchronous
def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

你和你的恋人一起去快餐店，你排队在后面，收银员从你前面的人接单。😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

然后轮到你了，你为你的恋人和你选了两个非常豪华的汉堡。🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

收银员对厨房里的厨师说了一些话，让他们知道他们必须为你准备汉堡（尽管他们目前正在为之前的顾客准备汉堡）。

<img src="/img/async/concurrent-burgers/concurrent-burgers-03.png" class="illustration">

你付钱了。 💸

收银员给你轮到的号码。