public void BatchUntaggingTest()
        {
            var tags = _userTagService.Get();
            var tag  = tags.FirstOrDefault();

            _userTagService.BatchTagging(tag.Id, new string[] { OpenId });
            var tt = _userTagService.Get(tag.Id);

            Assert.True(tt.Data.OpenIds.Contains(OpenId));

            _userTagService.BatchUntagging(tag.Id, new string[] { OpenId });

            tt = _userTagService.Get(tag.Id);
            Assert.False(tt.Data.OpenIds.Contains(OpenId));
        }