Node.hbm.xml

<?xml version="1.0" encoding="utf-8" ?> 
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-lazy="false">

    <class name="NHibernate.DomainModel.NHSpecific.Node, NHibernate.DomainModel"> 
		<id name="Id" column="id" type="String(10)" length="10">
			<generator class="assigned" />
		</id>
		
		<set name="DestinationNodes" table="node_link" lazy="true">
			<key column="from_node_id" />
			<many-to-many 
				column="to_node_id" 
				class="NHibernate.DomainModel.NHSpecific.Node, NHibernate.DomainModel" 
			/>
		</set>
		<set name="PreviousNodes" table="node_link" inverse="true">
			<key column="to_node_id" />
			<many-to-many 
				column="from_node_id" 
				class="NHibernate.DomainModel.NHSpecific.Node, NHibernate.DomainModel" 
			/>
		</set>
		
	</class>
</hibernate-mapping>