Cannot mapping collection by property-ref

I'm receive the following exception if I map collection by property-ref and it need to be created for more than one object:

NHibernate.LazyInitializationException : Initializing[NHibernate.Test.NHSpecificTest.NH3557.Person#5]-failed to lazily initialize a collection of role: NHibernate.Test.NHSpecificTest.NH3557.Person.Addresses, no session or session was closed