using System;
using System.Collections.Generic;

public partial class Data_Header
{
    public Data_Header()
    {
        this.Data_Lines = new HashSet<Data_Lines>();
    }

    public int DataHeaderID { get; set; }
    public System.Guid CmpWwn { get; set; }
    public System.Guid CntId { get; set; }
    public System.DateTime DeliveryDate { get; set; }
    public Nullable<int> DeliveryMethod_SysDeliveryMethodsID { get; set; }
    public System.DateTime DueDate { get; set; }

    public virtual Sys_DeliveryMethods Sys_DeliveryMethods { get; set; }
    public virtual vw_cicmpy vw_cicmpy { get; set; }
    public virtual ICollection<Data_Lines> Data_Lines { get; set; }
}

public class RequiredGuidAttribute : RequiredAttribute
{
    public override bool IsValid(object value)
    {
        var guid = CastToGuidOrDefault(value);

        return !Equals(guid, default(Guid));
    }

    private static Guid CastToGuidOrDefault(object value)
    {
        try
        {
            return (Guid)value;
        }
        catch (Exception e)
        {
            if (e is InvalidCastException || e is NullReferenceException) return default(Guid);
            throw;
        }
    }
}