public void RemoveImageTest()
        {
            // 준비
            Repository repository = new Repository();
            PictureRepo repo = new PictureRepo();
            ImageData data = repo.Get(91);
            int exifidx = data.ExifIdx.Value;
            int thumbidx = data.ThumbnailIdx.Value;

            // 실행
            repo.Remove(data.Idx);

            // 검증
            Assert.IsNull(repo.Get(91));
            Assert.IsNull(repository.Thumbnails.SingleOrDefault(model => model.Idx == thumbidx));
            Assert.IsNull(repository.Exifs.SingleOrDefault(model => model.Idx == exifidx));
        }