response_model_exclude_unset=True,
    response_model_exclude_none=True,
)
def get_exclude_unset_none() -> ModelDefaults:
    return ModelDefaults(x=None, y="y")


client = TestClient(app)


def test_return_defaults():
    response = client.get("/")
    assert response.json() == {"sub": {}}


def test_return_exclude_unset():
    response = client.get("/exclude_unset")
    assert response.json() == {"x": None, "y": "y"}