anchor.diff:  (defmethod (setf label-text) (new-text (self label))
     (set-label-text self new-text))
   
  +;;;----------------------------------------------------------------------------------------
   
   (defclass image (object)
     ((file-name :initarg :file-name :type string :reader image-file-name)))
  
positive.code: 
  
  
  
  (defclass window (object)
    ((color :initarg :color :initform "BLACK"    :type string :accessor object-color)
  
negative.code: (defmethod slider-value ((self slider))
    (slider.get-value self))
  
  ;;;----------------------------------------------------------------------------------------
  
  (defclass text-field (interactor)
    ((nchars :initarg :nchars :type int :reader text-field-nchars)))
  
  