anchor.diff:  		  (declare (ignore next-methods))
   		  (child-property-value (first args) slot-name)))))
   
  -(defmethod add-writer-method
  -    ((class child-class) generic-function slot-name)
  +(defmethod add-writer-method ((class container-child-class) generic-function slot-name)
     (add-method
      generic-function
      (make-instance 'standard-method
  
positive.code:   (declare (ignore args))
    (loop
     while (events-pending-p)
     do (main-iteration-do nil)))
  
  
  ;;;; Metaclass for child classes
  
negative.code: 	 (defclass ,child-class (,(default-container-child-name super))
  	   ,(slot-definitions child-class 
  	     (query-container-class-child-properties type) nil)
  	   (:metaclass container-child-class)
  	   (:container ,class))))))
  
  
  