public IQueryable <ContentChannelItem> ChangedContentChannelItemsByDate(DateTime changedSinceDate)
        {
            RockContext rockContext = new RockContext();
            IQueryable <ContentChannelItem> contentChannelItemList = new ContentChannelItemService(rockContext)
                                                                     .Queryable()
                                                                     .AsNoTracking()
                                                                     .Where(cci => (cci.CreatedDateTime >= changedSinceDate && cci.ModifiedDateTime == null) || cci.ModifiedDateTime >= changedSinceDate);

            IQueryable <ContentChannelItem> contentChannelItemList2 = new ContentChannelItemService(rockContext)
                                                                      .Queryable()
                                                                      .AsNoTracking()
                                                                      .WhereAttributeValue(rockContext, a => (a.CreatedDateTime >= changedSinceDate && a.ModifiedDateTime == null) || a.ModifiedDateTime >= changedSinceDate);

            return(contentChannelItemList.Union(contentChannelItemList2).AsQueryable());
        }