code: function( options ) {
  			var dit = this;
  			Backbone.Relational.eventQueue.add( function() {
  					Backbone.Model.prototype.change.apply( dit, arguments );
  				});
  		}
docs: Override 'change', so the change will only execute after 'set' has finised (relations are updated),
  and 'previousAttributes' will be available when the event is fired.