Для этого используйте `app.add_middleware()` (как в примере с CORS).

```Python
from fastapi import FastAPI
from unicorn import UnicornMiddleware

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

              "util.concurrent",
              "xml")
          .transform("com.google.common."::concat)
          .toSet();

  public void testClassesHaveOverrides() throws Exception {
    for (ClassInfo info : ClassPath.from(getClass().getClassLoader()).getAllClasses()) {
      if (!GUAVA_PACKAGES.contains(info.getPackageName())) {
        continue;
      }
      if (
      /*

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float


class ResponseMessage(BaseModel):
    message: str


class User(BaseModel):
    username: str
    email: str


@app.post("/items/", response_model=ResponseMessage, tags=["items"])
async def create_item(item: Item):
    return {"message": "Item received"}

from fastapi import FastAPI, Path
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int = Path(title="The ID of the item to get", ge=0, le=1000),
    q: str | None = None,
    item: Item | None = None,
):

from fastapi.testclient import TestClient

from docs_src.behind_a_proxy.tutorial002_py39 import app

client = TestClient(app)


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi():
    response = client.get("/openapi.json")
    assert response.status_code == 200
    assert response.json() == {

import importlib
from base64 import b64encode

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(
    name="client",
    params=[
        pytest.param("tutorial006_py39"),
        pytest.param("tutorial006_an_py39"),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.security.{request.param}")

    client = TestClient(mod.app)
    return client

   * "inherited" from superclasses of the same package.
   */
  public void testAllPublicStaticMethods(Class<?> c) {
    testStaticMethods(c, Visibility.PUBLIC);
  }

  /**
   * Runs {@link #testMethod} on every instance method of the class of {@code instance} with at
   * least {@code minimalVisibility}, including those inherited from superclasses of the same
   * package.
   */

        }
        // Can't map from a raw class to anything other than itself or a wildcard.
        // You can't say "assuming String is Integer".
        // And we don't support "assuming String is T"; user has to say "assuming T is String".
        throw new IllegalArgumentException("No type mapping from " + fromClass + " to " + to);
      }
    }.visit(from);
  }

  /**

     */
    public ServerData() {
        // Default constructor
    }

    /**
     * Server flags from the SMB header.
     */
    public byte sflags;
    /**
     * Server flags2 field from the SMB header.
     */
    public int sflags2;
    /**
     * Maximum number of outstanding multiplex requests.
     */
    public int smaxMpxCount;
    /**

    public String share; // Share
    /** The complete UNC path link */
    public String link;
    /** Path relative to tree from which this referral was thrown */
    public String path; // Path relative to tree from which this referral was thrown
    /** Whether to resolve hashes in the path */
    public boolean resolveHashes;
    /** Expiration time for this referral entry */
    public long expiration;