             }
             
             if isBold {
-                context.setFont(self.BoldLineNumberFont)
+                context.setFont(self.boldLineNumberFont)
             }
             
             // draw

            
            if isBold {
                // back to the regular font
                context.setFont(self.LineNumberFont)
            }
        }
        




// MARK: Line Number Font

private enum LineNumberFont {
    
    case regular
    case bold
    
    
    
    var font: NSFont {
        
        return NSFont(name: self.fontName, size: 0) ?? self.systemFont
    }
    
    
    var cgFont: CGFont {
        
        return CTFontCopyGraphicsFont(self.font, nil)
    }
    
    
    /// name of the first candidate font
    private var fontName: String {
        
        switch self {
        case .regular:
            return "AvenirNextCondensed-Regular"
        case .bold:
            return "AvenirNextCondensed-Bold"
        }
    }
    
    
    /// system font for fallback
    private var systemFont: NSFont {
        
        if #available(macOS 10.11, *) {
            return NSFont.monospacedDigitSystemFont(ofSize: 0, weight: self.weight)
        } else {
            return NSFont.paletteFont(ofSize: 0)
        }
    }
    
    
    /// font weight for system font
    @available(macOS 10.11, *)
    private var weight: CGFloat {
        
        switch self {
        case .regular:
            return NSFontWeightRegular
        case .bold:
            return NSFontWeightBold
        }
    }
    
}



// MARK: Private Int helpers

private extension Int {
