问单向一对多关系的NHibernate配置？

public class Detail {
    public virtual Guid DetailId { get; set; }
    public virtual string Name { get; set; }
}
public class Master {
    public virtual Guid MasterId { get; set; }
    public virtual string Name { get; set; }
    public virtual IList<Detail> Details { get; set; }
}

public class MasterMap : ClassMap<Master> 
{
    public MasterMap() 
    {
        Id(x => x.MasterId);
        Map(x => x.Name);
        HasMany(x => x.Details).Not.KeyNullable.Cascade.All();
    }
}
public class DetailMap : ClassMap<Detail> 
{
    public DetailMap() 
    {
        Id(x => x.Id);
        Map(x => x.Name);
    }
}

masterId   uniqueidentifier NOT NULL
name       nvarchar(max) NULL

DetailId   uniqueidentifier NOT NULL
name       nvarchar(max) NULL
MasterId   uniqueidentifier NULL
foreign key (masterId) references [Master]使用如下代码：

Master mast = new Master 
{
    MasterId = new Guid(),
    Name = "test",
    Details = new List<Detail> 
    {
        new Detail { .DetailId = new Guid(), .Name = "Test1" },
        new Detail { .DetailId = new Guid(), .Name = "Test1" }
    }
};

using (transaction == Session.BeginTransaction) 
{
    Session.Save(mast);
    transaction.Commit();
}