public class Class1
{
  public virtual int Class1Id {get; set;}
  public virtual IList<int> Values {get; protected set;}
  public Class1()
  {
    Values = new List<int>();
  }
}

public Class1Map: Map<Class1>
{
  public Class1Map()
  {
      Id(x => x.Class1Id)
            .UniqueKey("Class1Id")
            .GeneratedBy.HiLo("NHHiLoIdentity", "NextHiValue", "1000", "Entity = [Class1]'");

       HasMany<int>(x => x.Values )
            .Element("Class1Value")
            .KeyColumn("Class1Id")
            .Table("Class1Values")
            .Cascade.All();
  }
}

var class1 = new Class1();
class1.Values.Add(1)
class1.Values.Add(2)
statelessSession.Insert(class1);