anchor.diff:  another.")
   
        (constructor nil
  -                  :type (or null function)
  +                  :type (or null list function)
                     :documentation
                     "Function called with the source as argument.
   The returned value is assigned to `initial-suggestions'.
  
positive.code: 
       (initial-suggestions '()
                            :reader initial-suggestions
                            :export t
                            :documentation
                            "Suggestions used on initialization, before any
  user input is processed.
  
negative.code:        (bt:acquire-lock (initial-suggestions-lock source))
         (calispel:? wait-channel)
         ;; `initial-suggestions' initialization must be done before first input can be processed.
         (cond ((listp (constructor source))
                (setf (slot-value source 'initial-suggestions)
                      (constructor source)))
               ((constructor source)
                (setf (slot-value source 'initial-suggestions)
                      (funcall (constructor source) source))))
         (setf (slot-value source 'initial-suggestions)
               (ensure-suggestions-list source (initial-suggestions source)))
         ;; TODO: Setting `suggestions' is not needed?
  