@staticmethod
def _fetch_request_info(request):
    """
        Preserve the cached image id, version for consumption by the
        process_response method of this middleware
        """
    try:
        image_id = request.environ['api.cache.image_id']
        method = request.environ['api.cache.method']
        version = request.environ['api.cache.version']
    except KeyError:
        return None
    else:
        return image_id, method, version
