How to use the whitenoise.middleware.WhiteNoiseFileResponse function in whitenoise

def test_whitenoise_file_response_has_only_one_header():
    response = WhiteNoiseFileResponse(open(__file__, "rb"))
    response.close()
    headers = {key.lower() for key, value in response.items()}
    # This subclass should have none of the default headers that FileReponse
    # sets
    assert headers == {"content-type"}

def serve(static_file, request):
        response = static_file.get_response(request.method, request.META)
        status = int(response.status)
        http_response = WhiteNoiseFileResponse(response.file or (), status=status)
        # Remove default content-type
        del http_response["content-type"]
        for key, value in response.headers:
            http_response[key] = value
        return http_response