anchor.diff:  
   (defclass text-configuration-schema-option-type (configuration-schema-option-type)
     ()
  -  (:documentation "Fill in some text"))
  +  (:documentation "Text type"))
   
   (defmethod title ((type text-configuration-schema-option-type))
     "Text")
  +
  +(defclass integer-configuration-schema-option-type (configuration-schema-option-type)
  +  ()
  +  (:documentation "Integer type"))
  +
  +(defmethod title ((type integer-configuration-schema-option-type))
  +  "Integer")
   
   (defclass list-configuration-schema-option-type (configuration-schema-option-type)
     ((options :initarg :options
  
positive.code:   (declare (ignore args))
    (make-instance 'boolean-configuration-schema-option-type))
  
  (define-configuration-schema-option-type :sexp (&rest args)
    (declare (ignore args))
    (make-instance 'sexp-configuration-schema-option-type))
  
negative.code:     (value option)
    (stringp value)
    "~A should be a string" value)
  
  (define-option-validator integer-configuration-schema-option-type
      (value option)
    (integerp value)
    "~A should be an integer" value)
  
  (define-option-validator one-of-configuration-schema-option-type
      (value option)
  