def get_root() -> ModelSubclass:
    return ModelSubclass(sub={}, y=1, z=0)


@app.get(
    "/exclude_unset", response_model=ModelDefaults, response_model_exclude_unset=True
)
def get_exclude_unset() -> ModelDefaults:
    return ModelDefaults(x=None, y="y")


@app.get(
    "/exclude_defaults",
    response_model=ModelDefaults,
    response_model_exclude_defaults=True,
)