         
         guard self.replace(with: replacementStrings, ranges: selectedRanges, selectedRanges: newSelectedRanges) else { return false }
         
+        // store last used string pair
         UserDefaults.standard[.beginCustomSurroundString] = begin
         UserDefaults.standard[.endCustomSurroundString] = end
         

        self.viewControllerForSheet?.presentAsSheet(self.customSurroundStringViewController)
    }
    
    
    func instantinateSurroundStringViewController() -> NSViewController {
        
        let viewController = CustomSurroundStringViewController.instantiate(storyboard: "CustomSurroundStringView")

        return viewController
    }
    
    
    /// insert strings around selections
    @discardableResult
