partial void DeleteRelation(Relation instance);
 partial void UpdateRelation(Relation instance);
		private void detach_Relations(Relation entity)
		{
			this.SendPropertyChanging();
			entity.Node = null;
		}
 partial void InsertRelation(Relation instance);
		private void attach_Relations(Relation entity)
		{
			this.SendPropertyChanging();
			entity.Node = this;
		}