anchor.diff:     (background-buffer nil
                         :documentation "The buffer to host background page of the extension in.
   Is shared between all the instances of the same extension.")
  +   (popup-buffer nil
  +                 :type (or null panel-buffer)
  +                 :documentation "The panel-buffer to host extension popup in.
  +Is only set when popup is active.")
      (description nil
                   :type (or null string))
      (homepage-url nil
  
positive.code:                     (browser-action (browser-action extension))
                      (default-popup (default-popup browser-action))
                      (popup (make-instance 'user-panel-buffer
                                            :title (default-title (browser-action extension)))))
        (nyxt::window-add-panel-buffer
         (current-window) popup
         :right)
        (buffer-load (quri.uri.file:make-uri-file :path (merge-extension-path extension default-popup))
                     :buffer popup))))
  
  
negative.code:               :allocation :class)
            (background-buffer nil
                               :allocation :class)
            (popup-buffer nil
                          :allocation :class)
            (description ,(alex:assoc-value json :description))
            (extension-directory ,directory)
            (homepage-url ,(alex:assoc-value json :homepage--url))
  