public static void SetCategoryId(this MetaCollection metaCollection, int categoryParentId, int categoryId, object value = null)
        {
            MetaEntity meta;

            if ((meta = metaCollection.FirstOrDefault(x => x.CategoryParentId == categoryParentId)) != null)
            {
                meta.CategoryId = categoryId;
                meta.MetaValue  = value;
            }
            else
            {
                metaCollection.Add(new MetaEntity()
                {
                    CategoryParentId = categoryParentId, CategoryId = categoryId, MetaValue = value
                });
            }
        }
        public static int?GetCategoryId(this MetaCollection metaCollection, int categoryParentId)
        {
            MetaEntity meta;

            return((meta = metaCollection.FirstOrDefault(x => x.CategoryParentId == categoryParentId)) != null ? meta.CategoryId : (int?)null);
        }