def METHOD_NAME(body, headers):
    """Wrapper for a callback function for responses.add_callback"""
    def request_callback(request):
        if request.headers["content-type"] == "application/json":
            assert json.loads(request.body) == body
        else:
            assert request.body == body
        assert (request.headers[key] == headers[key] for key in headers)
        return 200, {}, json.dumps({"proxy": True})
    return request_callback