使用Nhibernate Criteria Api查询集合？

using NHibernate;
using NHibernate.Criterion;

public IList<Cat> GetCatsByColor(string color)
{
    using (var session = sessionFactory.OpenSession())
    {
        using (var transaction = session.BeginTransaction())
        {
            var criteria = session.CreateCriteria<Cat>()
                .Add(Restrictions.Eq("Color", color));

            var cats = criteria.List<Cat>();

            transaction.Commit();

            return cats;
        }
    }
}