默认情况下是否所有NHibernate引用都是Lazyload?

我有一个(虚构的)具有流畅映射的类:

public class Customer 
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual Employee Responsible { get; set; }
    public virtual IList<Order> Orders { get; set; }
}

public class CustomerMapping : ClassMap<Customer    
{
    public CustomerMapping()
    {
        Id(c => c.Id);
        Map(c => c.Name);
        References(c => c.Responsible);
        HasMany(c => c.Orders); 
    }
}

现在-如果我从数据库中获取一个客户,那么HasMany引用是Lazyload的,但引用引用似乎不是Lazy加载的。这是预期的吗?我需要明确地说出来吗?

var fromDb = Session.Get<Customer>(id); 
Assert.That(!NHibernateUtil.IsInitialized(fromDb.Orders));
Assert.That(!NHibernateUtil.IsInitialized(fromDb.Reponsible)); // <-- fails