anchor.diff:                            :border-width 0))
             (button
              (make-instance 'gtk:gtk-button
  -                          :label "Browser View Placeholder"))
  +                          :label "About:Blank"))
             (entry
              (make-instance 'gtk:gtk-entry
                             :text "Minibuffer Input"))
             (root-box
  +           (make-instance 'gtk:gtk-box
  +                          :orientation :vertical
  +                          :spacing 0))
  +          (container-box
              (make-instance 'gtk:gtk-box
                             :orientation :vertical
                             :spacing 0))
  
positive.code:           (column (gtk:gtk-tree-view-column-new-with-attributes
                     "Name" renderer "text" 0)))
       (gtk:gtk-tree-view-append-column list-view column)
       (gtk:gtk-list-store-set model (gtk:gtk-list-store-append model) "Element 1")
       (gobject:g-signal-connect window "destroy"
                                 (lambda (widget)
                                   (declare (ignore widget))
                                   (gtk:leave-gtk-main)))
       (gtk:gtk-box-pack-start root-box button)
       (gtk:gtk-box-pack-start root-box minibuffer-box :expand nil)
       (gtk:gtk-box-pack-start minibuffer-box entry :expand nil)
       (gtk:gtk-box-pack-start minibuffer-box list-view :expand nil)
       (gtk:gtk-container-add window root-box)
       (setf *next-interface* (make-instance
                               'next-interface
                               :window window
                               :minibuffer-view (make-instance
                                                 'minibuffer-view
                                                 :container-view minibuffer-box
  
negative.code: (defclass minibuffer-view ()
    ((container-view :accessor container-view :initarg :container-view)
     (input-entry :accessor input-entry :initarg :input-entry)
     (completions :accessor completions)
     (completion-model :accessor completion-model :initarg :completion-model)
     (completion-view :accessor completion-view :initarg :completion-view)
     (completion-function :accessor completion-function)))
  