private bool CanSaveCommandExecute()
        {
            bool isCategoryNameUnique = true;

            if (categories.FirstOrDefault(a => a.CategoryName == CategoryName) != null && isAddition)
            {
                isCategoryNameUnique = false;
            }

            if (string.IsNullOrEmpty(CategoryName) || SelectedType == null || CategoryName.Any(a => char.IsDigit(a)) || !isCategoryNameUnique)
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }