## Example

```python
from fastapi import FastAPI, status

app = FastAPI()


@app.get("/items/", status_code=status.HTTP_418_IM_A_TEAPOT)
def read_items():
    return [{"name": "Plumbus"}, {"name": "Portal Gun"}]
```

import subprocess

from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")

import com.google.gson.Gson
import com.google.gson.stream.JsonWriter

class AcceptedApiChangesJsonFileManager {

    void emptyAcceptedApiChanges(File jsonFile) {
        jsonFile.withWriter { fileWriter ->
            def writer = new JsonWriter(fileWriter)
            writer.setIndent("    ")
            new Gson().toJson([acceptedApiChanges: []], Object, writer)
            writer.close()
        }
    }

import subprocess
import time

import httpx
from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()

    @PathSensitive(PathSensitivity.ABSOLUTE)
    @InputDirectory
    abstract DirectoryProperty getJsonFileDirectory()

    @TaskAction
    void clean() {
        def jsonFileManager = new AcceptedApiChangesJsonFileManager()
        jsonFileDirectory.asFile.get().listFiles()
            ?.findAll { it.name.endsWith(".json") }
            ?.each { jsonFileManager.emptyAcceptedApiChanges(it) }

from starlette.concurrency import (  # noqa
    run_until_first_complete as run_until_first_complete,
)

_T = TypeVar("_T")


@asynccontextmanager
async def contextmanager_in_threadpool(
    cm: AbstractContextManager[_T],
) -> AsyncGenerator[_T, None]:
    # blocking __exit__ from running waiting on a free thread
    # can create race conditions/deadlocks if the context manager itself

import subprocess
import time

import httpx
from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    browser = playwright.chromium.launch(headless=False)

    server.enqueue(MockResponse(body = "abc"))
    server.enqueue(MockResponse(body = "def"))

    val request = Request(server.url("/"))

    val call = client.newCall(request)
    val response1 = call.execute()

    val cloned = call.clone()
    val response2 = cloned.execute()

    assertThat("abc").isEqualTo(response1.body.string())
    assertThat("def").isEqualTo(response2.body.string())
  }

  @Test
  @Flaky

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Or use <code>async def</code>...</summary>

If your code uses `async` / `await`, use `async def`:

```Python hl_lines="9  14"

from docs_src.app_testing.tutorial004_py39 import test_read_items


def test_main():