taskRunner: TaskRunner,
          nanos: Long,
        ) {
          taskRunner.assertThreadHoldsLock()
          check(waitingCoordinatorTask == null)
          if (nanos == 0L) return

          // Yield until notified, interrupted, or the duration elapses.
          val waitUntil = nanoTime + nanos
          val self = currentTask
          waitingCoordinatorTask = self
          waitingCoordinatorNotified = false

from fastapi.testclient import TestClient


@pytest.fixture(name="app", scope="module")
def get_app():
    with pytest.warns(DeprecationWarning):
        from docs_src.events.tutorial001 import app
    yield app


def test_events(app: FastAPI):
    with TestClient(app) as client:
        response = client.get("/items/foo")
        assert response.status_code == 200, response.text

from fastapi import Depends, FastAPI, HTTPException, Query
from sqlmodel import Field, Session, SQLModel, create_engine, select


class HeroBase(SQLModel):
    name: str = Field(index=True)
    age: Union[int, None] = Field(default=None, index=True)


class Hero(HeroBase, table=True):
    id: Union[int, None] = Field(default=None, primary_key=True)
    secret_name: str


class HeroPublic(HeroBase):
    id: int

    static_dir: Path = Path(os.getcwd()) / "static"
    print(static_dir)
    static_dir.mkdir(exist_ok=True)
    from docs_src.custom_docs_ui.tutorial001 import app

    with TestClient(app) as client:
        yield client
    static_dir.rmdir()


def test_swagger_ui_html(client: TestClient):
    response = client.get("/docs")
    assert response.status_code == 200, response.text

1. This is the generator function. It's a "generator function" because it contains `yield` statements inside.
2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.
3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

```{ .python .annotate hl_lines="2  10-12  14" }
{!../../docs_src/custom_response/tutorial008.py!}
```

1️⃣. 👉 🚂 🔢. ⚫️ "🚂 🔢" ↩️ ⚫️ 🔌 `yield` 📄 🔘.
2️⃣. ⚙️ `with` 🍫, 👥 ⚒ 💭 👈 📁-💖 🎚 📪 ⏮️ 🚂 🔢 🔨. , ⏮️ ⚫️ 🏁 📨 📨.
3️⃣. 👉 `yield from` 💬 🔢 🔁 🤭 👈 👜 🌟 `file_like`. & ⤴️, 🔠 🍕 🔁, 🌾 👈 🍕 👟 ⚪️➡️ 👉 🚂 🔢.

    , ⚫️ 🚂 🔢 👈 📨 "🏭" 👷 🕳 🙆 🔘.

* It can do something to that **response** or run any needed code.
* Then it returns the **response**.

/// note | "Technical Details"

If you have dependencies with `yield`, the exit code will run *after* the middleware.

If there were any background tasks (documented later), they will run *after* all the middleware.

///

## Create a middleware

                        "timed out waiting for other threads to block"
                            + " synchronizing on supplier"));
                break;
              }
              Thread.yield();
            }
            count.getAndIncrement();
            return Boolean.TRUE;
          }
        };

    final Supplier<Boolean> memoizedSupplier = memoizer.apply(supplier);

                        "timed out waiting for other threads to block"
                            + " synchronizing on supplier"));
                break;
              }
              Thread.yield();
            }
            count.getAndIncrement();
            return Boolean.TRUE;
          }
        };

    final Supplier<Boolean> memoizedSupplier = memoizer.apply(supplier);

* ⚫️ 💪 ⤴️ 🕳 👈 **📨** ⚖️ 🏃 🙆 💪 📟.
* ⤴️ ⚫️ 🚶‍♀️ **📨** 🛠️ 🎂 🈸 ( *➡ 🛠️*).
* ⚫️ ⤴️ ✊ **📨** 🏗 🈸 ( *➡ 🛠️*).
* ⚫️ 💪 🕳 👈 **📨** ⚖️ 🏃 🙆 💪 📟.
* ⤴️ ⚫️ 📨 **📨**.

/// note | "📡 ℹ"

🚥 👆 ✔️ 🔗 ⏮️ `yield`, 🚪 📟 🔜 🏃 *⏮️* 🛠️.

🚥 📤 🙆 🖥 📋 (📄 ⏪), 👫 🔜 🏃 *⏮️* 🌐 🛠️.

///

## ✍ 🛠️

✍ 🛠️ 👆 ⚙️ 👨‍🎨 `@app.middleware("http")` 🔛 🔝 🔢.

🛠️ 🔢 📨:

*  `request`.