public object GetValue(string NameValue)
        {
            Type   typeValue = Types[NameValue];
            object ret;

            try
            {
                if (typeValue == typeof(DateTime))
                {
                    ret = Convert.ChangeType
                          (
                        Attr_item.FirstOrDefault(val => val.Attr_name == NameValue).Value,
                        typeValue,
                        new CultureInfo("Ru-ru")
                          );
                }
                else
                {
                    ret = Convert.ChangeType
                          (
                        Attr_item.FirstOrDefault(val => val.Attr_name == NameValue).Value,
                        typeValue,
                        CultureInfo.InvariantCulture
                          );
                }
            }
            catch (Exception)
            {
                ret = null;
            }
            return(ret);
        }
 public string Print()
 => $"Art_listArt_item: Art_id={Art_id}, Designation={Designation}, Name={Name}, Section_id={Section_id}\r\n\t" +
 string.Join("\r\n\t", Attr_item.Select(item => item.Print()));