 
     @IBAction func changeFilterFromMatrix(_ sender: AnyObject?) {
         let matrix = sender as! NSMatrix
-        self.changeFilter(matrix.selectedCell())
+        changeFilter(matrix.selectedCell())
     }
 
     @IBAction func setChannelRadioButton(_ sender: AnyObject?) {

    }

    private func refreshMessagesTableView() {
        updateDisplayedMessages()

        // Scroll to the botton, iff the table view is already scrolled to the bottom.
        let isAtBottom = messagesTableView.bounds.maxY - messagesTableView.visibleRect.maxY < messagesTableView.rowHeight

            guard let document = document else { return }
            guard let smmDocument = document as? SMMDocument else { fatalError() }

            _ = window // Make sure the window and all views are loaded first

            updateMessages(scrollingToBottom: false)
            updateSources()
