async def METHOD_NAME(factory: Callable, method: HttpMethod) -> None:
    headers = {"header1": "value1"}
    request = factory("/", headers=headers, data=pet)
    assert request.method == method
    # Headers should include "header1" and "Content-Type"
    assert len(request.headers.keys()) == 3
    assert request.headers.get("header1") == "value1"
    body = await request.body()
    assert json.loads(body) == _model_dump(pet)