* objects come from factory methods that are themselves {@code @Nullable}. In reality neither the
   * array nor its contents can be null, but it is not useful to force the use of {@code
   * requireNonNull} or the like just to assert that.
   *
   * <p>{@code EqualsTester} will always check that every object it is given returns false from

from typing import Optional

from dirty_equals import IsDict
from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


user_router = APIRouter()
item_router = APIRouter()


@user_router.get("/")
def get_users():
    return [{"user_id": "u1"}, {"user_id": "u2"}]


@user_router.get("/{user_id}")
def get_user(user_id: str):
    return {"user_id": user_id}

# Controllers

Istio has a variety of [controllers](https://kubernetes.io/docs/concepts/architecture/controller/), which basically watch some inputs and do something.
This can be reading from Kubernetes and writing other objects back, writing to proxies over XDS, etc.

Unfortunately, writing controllers is very error prone, even for seemingly simple cases.
To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

// If it fails to dial all IPs from cache it returns first error. If no baseDialFunc
// is given, it sets default dial function.
//
// You can use returned dial function for `http.Transport.DialContext`.
//
// In this function, it uses functions from `rand` package. To make it really random,
// you MUST call `rand.Seed` and change the value from the default in your application

as if it had a "vendor/" prefix. For example, within "crypto/tls",
an import of "golang.org/x/crypto/cryptobyte" resolves to
"vendor/golang.org/x/crypto/cryptobyte". When a package with the
same path is imported from a package outside std or cmd, it will
be resolved normally. Consequently, a binary may be built with two
copies of a package at different versions if the package is
imported normally and vendored by the standard library.

     * @return {@link List} $lt; {@link ArtifactVersion} >
     * @throws ArtifactMetadataRetrievalException
     *          in case of error while retrieving repository metadata from the repository.
     */
    List<ArtifactVersion> retrieveAvailableVersions(
            Artifact artifact, ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories)

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.body_fields.tutorial001_an import app

    client = TestClient(app)
    return client


def test_items_5(client: TestClient):
    response = client.put("/items/5", json={"item": {"name": "Foo", "price": 3.0}})
    assert response.status_code == 200
    assert response.json() == {

from dirty_equals import IsDict
from fastapi.testclient import TestClient

from docs_src.request_files.tutorial001_02 import app

client = TestClient(app)


def test_post_form_no_body():
    response = client.post("/files/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "No file sent"}


def test_post_uploadfile_no_body():
    response = client.post("/uploadfile/")

```Python hl_lines="1  46-47"
{!../../docs_src/websockets/tutorial001.py!}
```

/// note | "Technical Details"

You could also use `from starlette.websockets import WebSocket`.

**FastAPI** provides the same `WebSocket` directly just as a convenience for you, the developer. But it comes directly from Starlette.

///

## Await for messages and send messages

In your WebSocket route you can `await` for messages and send messages.

from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/a/{id}")
async def a(id):
    pass  # pragma: no cover


client = TestClient(app)


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},