   redo: ->
     _change.call(this, 'redo', 'undo')
 
+  ###
   transformExternal: (delta) ->
     return if delta.isIdentity()
     @stack['undo'] = _.map(@stack['undo'], (change) ->

        undo: change.undo.follows(delta, true)
      }
    )

  undo: ->
    _change.call(this, 'undo', 'redo')

      this.record(delta, @oldDelta) unless @ignoringChanges
      @oldDelta = @editor.getDelta()
    ).on(Scribe.Editor.events.API_TEXT_CHANGE, (delta) =>
      this.record(delta, @oldDelta)
      @oldDelta = @editor.getDelta()
    )

