public async Task <string> Invoke()
        {
            var file = $"{WorkspaceId}/{LayerId}.mbtiles";

            if (await _tileStorage.Exist(file))
            {
                return(await _tileStorage.GetMd5($"{WorkspaceId}/{LayerId}.mbtiles"));
            }
            throw new EntityNotFoundException();
        }
        public async Task <ActionResult> Invoke()
        {
            var file = $"{WorkspaceId}/{LayerId}.mbtiles";

            if (await _tileStorage.Exist(file))
            {
                return(Redirect(await _tileStorage.GetDownloadUrl(file)));
            }
            throw new EntityNotFoundException();
        }