/// <summary>
        /// Returns all the Names of the user-defined cells
        /// </summary>
        /// <remarks>
        /// names of user defined cells are not queryable get GetResults & GetFormulas
        /// </remarks>
        /// <param name="shape"></param>
        /// <returns></returns>
        public static IList <string> GetNames(IVisio.Shape shape)
        {
            if (shape == null)
            {
                throw new System.ArgumentNullException(nameof(shape));
            }

            int user_prop_row_count = UserDefinedCellsHelper.GetCount(shape);

            if (user_prop_row_count < 1)
            {
                return(new List <string>(0));
            }

            var prop_names   = new List <string>(user_prop_row_count);
            var prop_section = shape.Section[UserDefinedCellsHelper._userdefinedcell_section];
            var query_names  = prop_section.AsEnumerable().Select(row => row.NameU);

            prop_names.AddRange(query_names);

            if (user_prop_row_count != prop_names.Count)
            {
                throw new AutomationException("Unexpected number of user-defined-cell names");
            }

            return(prop_names);
        }
        /// <summary>
        /// Gets all the user properties defined on a shape
        /// </summary>
        /// <remarks>
        /// If there are no user properties then null will be returned</remarks>
        /// <param name="shape"></param>
        /// <returns>A list of user  properties</returns>
        public static IList <UserDefinedCell> Get(IVisio.Shape shape)
        {
            if (shape == null)
            {
                throw new System.ArgumentNullException(nameof(shape));
            }

            var prop_count = UserDefinedCellsHelper.GetCount(shape);

            if (prop_count < 1)
            {
                return(new List <UserDefinedCell>(0));
            }

            var prop_names = UserDefinedCellsHelper.GetNames(shape);

            if (prop_names.Count != prop_count)
            {
                throw new AutomationException("Unexpected number of prop names");
            }

            var shape_data = UserDefinedCell.GetCells(shape);

            var list = new List <UserDefinedCell>(prop_count);

            for (int i = 0; i < prop_count; i++)
            {
                shape_data[i].Name = prop_names[i];
                list.Add(shape_data[i]);
            }

            return(list);
        }