mu := NewDRWMutex(ds, "")
	if slack {
		b.SetParallelism(10)
	}
	b.RunParallel(func(pb *testing.PB) {
		foo := 0
		for pb.Next() {
			mu.Lock(id, source)
			mu.Unlock(context.Background())
			if work {
				for i := 0; i < 100; i++ {
					foo *= 2
					foo /= 2
				}
			}
		}
		_ = foo
	})
}

func BenchmarkMutex(b *testing.B) {
	benchmarkMutex(b, false, false)
}

An error on not-declared:1 indicates that foo is undeclared.
An error on not-type:1 indicates that foo is not a type (if declared at all, it is an identifier).
An error on not-int-const:1 indicates that foo is not an integer constant.
An error on not-num-const:1 indicates that foo is not a number constant.
An error on not-str-lit:1 indicates that foo is not a string literal.
An error on not-signed-int-const:1 indicates that foo is not a signed integer constant.

Ce qui fait qu'avec une URL comme :

```
http://localhost:8000/items/?q=foo&q=bar
```

vous recevriez les valeurs des multiples paramètres de requête `q` (`foo` et `bar`) dans une `list` Python au sein de votre fonction de **path operation**, dans le paramètre de fonction `q`.

Donc la réponse de cette URL serait :

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

/// tip | "Astuce"

        }
    )


def test_users_foo_token_jessica(client: TestClient):
    response = client.get("/users/foo?token=jessica")
    assert response.status_code == 200
    assert response.json() == {"username": "foo"}


def test_users_foo_with_no_token(client: TestClient):
    response = client.get("/users/foo")
    assert response.status_code == 422
    assert response.json() == IsDict(
        {
            "detail": [

```Python hl_lines="11"
{!../../docs_src/handling_errors/tutorial001.py!}
```

### 📉 📨

🚥 👩‍💻 📨 `http://example.com/items/foo` ( `item_id` `"foo"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 2️⃣0️⃣0️⃣, & 🎻 📨:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

✋️ 🚥 👩‍💻 📨 `http://example.com/items/bar` (🚫-🚫 `item_id` `"bar"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 4️⃣0️⃣4️⃣ ("🚫 🔎" ❌), & 🎻 📨:

```

////

👉 🔜 ⛓ 👈 **FastAPI** 🔜 ⌛ 💪 🎏:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

🔄, 🤸 👈 📄, ⏮️ **FastAPI** 👆 🤚:

* 👨‍🎨 🐕‍🦺 (🛠️, ♒️), 🐦 🏷

foo...

foo...

foo...

foo...