public static DirectedRelationship GetDirectedMappedRelationship(Entity entity, Reference reference)
        {
            Relationship relationship = reference.MappedRelationship();
            if (relationship == null)
                throw new NHibernateMappingException("Could not find mapped relationship for Reference: " +
                                                     reference.Name);

            ITable mappedTable = EntityMapper.GetPrimaryTable(entity);
            return new DirectedRelationship(relationship, mappedTable);
        }