def create_swagger_json_handler(app, **kwargs):
    """
    Create a handler that returns the swagger definition
    for an application.

    This method assumes the application is using the
    TransmuteUrlDispatcher as the router.
    """

    spec = getattr(app, SWAGGER_ATTR_NAME, SwaggerSpec())
    _add_blueprint_specs(app, spec)
    spec_dict = spec.swagger_definition(**kwargs)
    encoded_spec = json.dumps(spec_dict).encode("UTF-8")

    def swagger():
        return Response(
            encoded_spec,
            # we allow CORS, so this can be requested at swagger.io
            headers={
                "Access-Control-Allow-Origin": "*"
            },
            content_type="application/json",
        )

    return swagger