         return inches.converter.value(fromBaseUnitValue: baseUnitValue) * 8
     }
     
-    private override func copy() -> AnyObject {
-        return self
-    }
-    
-    private func copy(with zone: NSZone? = nil) -> AnyObject {
+    func copy(with zone: NSZone? = nil) -> Any {
         return self
     }
     

        return inches.converter.value(fromBaseUnitValue: baseUnitValue) * 16
    }
    
    private override func copy() -> AnyObject {
        return self
    }
    
    private func copy(with zone: NSZone? = nil) -> AnyObject {
        return self
    }
    

        context.setShouldAntialias(false)
        
        for offset in xOffsets(for: unit) {
            context.move(to: CGPoint(x: offset, y: 0))
            context.addLine(to: CGPoint(x: offset, y: height))
            
            context.move(to: CGPoint(x: offset, y: bounds.maxY))
            context.addLine(to: CGPoint(x: offset, y: bounds.maxY - height))
            
            context.strokePath()
        }
