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),
):
    return {"client_id": client_key, "client_tag": client_tag}


client = TestClient(app)

expected_schema = {
    "components": {
        "schemas": {
            "HTTPValidationError": {