[
        ("/items", None, 200, {"ads_id": None}),
        ("/items", {"ads_id": "ads_track"}, 200, {"ads_id": "ads_track"}),
        (
            "/items",
            {"ads_id": "ads_track", "session": "cookiesession"},
            200,
            {"ads_id": "ads_track"},
        ),
        ("/items", {"session": "cookiesession"}, 200, {"ads_id": None}),
    ],
)

👯‍♂️ 💼 👉 ⛓ 👈 `item` 💪 `int` ⚖️ `str`.

#### 🎲 `None`

👆 💪 📣 👈 💲 💪 ✔️ 🆎, 💖 `str`, ✋️ 👈 ⚫️ 💪 `None`.

🐍 3️⃣.6️⃣ & 🔛 (✅ 🐍 3️⃣.1️⃣0️⃣) 👆 💪 📣 ⚫️ 🏭 & ⚙️ `Optional` ⚪️➡️ `typing` 🕹.

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

⚙️ `Optional[str]` ↩️ `str` 🔜 ➡️ 👨‍🎨 ℹ 👆 🔍 ❌ 🌐❔ 👆 💪 🤔 👈 💲 🕧 `str`, 🕐❔ ⚫️ 💪 🤙 `None` 💁‍♂️.

		b := make([]byte, 12)
		_, terr = deadlineconn.Read(b)
		if terr != nil {
			t.Errorf("failed to read from client. %v", terr)
			return
		}
		received := string(b)
		if received != "message one\n" {
			t.Errorf(`server: expected: "message one\n", got: %v`, received)
			return
		}

		// Wait for more than read timeout to simulate processing.
		time.Sleep(3 * time.Second)

		_, terr = deadlineconn.Read(b)
		if terr != nil {

	dm.Unlock(context.Background())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(context.Background())
}

// Test two locks for same resource, one succeeds, one fails (after timeout)
func TestTwoSimultaneousLocksForSameResource(t *testing.T) {
	dm1st := NewDRWMutex(ds, "aap")
	dm2nd := NewDRWMutex(ds, "aap")

	dm1st.Lock(id, source)

  if expr "$link" : '/.*' > /dev/null; then
    SCRIPT="$link"
  else
    SCRIPT=`dirname "$SCRIPT"`/"$link"
  fi
done

# determine fess home
FESS_HOME=`dirname "$SCRIPT"`/..

# make FESS_HOME absolute
FESS_HOME=`cd "$FESS_HOME"; pwd`


# If an include wasn't specified in the environment, then search for one...
if [ "x$FESS_INCLUDE" = "x" ]; then
    # Locations (in order) to use when searching for an include file.

    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "message": "Hello Users!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }


@needs_py310
def test_override_in_users_with_q():
    from docs_src.dependency_testing.tutorial001_an_py310 import client

    response = client.get("/users/?q=foo")

    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "message": "Hello Users!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }


@needs_py39
def test_override_in_users_with_q():
    from docs_src.dependency_testing.tutorial001_an_py39 import client

    response = client.get("/users/?q=foo")

    [
        ("/items", None, 200, {"ads_id": None}),
        ("/items", {"ads_id": "ads_track"}, 200, {"ads_id": "ads_track"}),
        (
            "/items",
            {"ads_id": "ads_track", "session": "cookiesession"},
            200,
            {"ads_id": "ads_track"},
        ),
        ("/items", {"session": "cookiesession"}, 200, {"ads_id": None}),
    ],
)

app = FastAPI()


def _get_client_key(client_id: str = Query(...)) -> str:
    return f"{client_id}_key"


def _get_client_tag(client_id: Optional[str] = Query(None)) -> Optional[str]:
    if client_id is None:
        return None
    return f"{client_id}_tag"


@app.get("/foo")
def foo_handler(
    client_key: str = Depends(_get_client_key),
    client_tag: Optional[str] = Depends(_get_client_tag),
):

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[list[str] | None, Query()] = None):
    query_items = {"q": q}