     // MARK: - Public Methods
     public func update(backgroundImage: UIImage?) {
         self.backgroundImageView.image = backgroundImage
-        self.session.append(self.currentPaper())
+        self.session.append(self.currentDrawing())
         self.saved = self.canSave()
         self.didUpdateCanvas()
     }

    
    private func didUpdateCanvas() {
        let mergedImage = self.mergePathsAndImages()
        let currentPaper = self.currentPaper()
        self.delegate?.canvas?(self, didUpdateDrawing: currentPaper, mergedImage: mergedImage)
    }
    

        return data1!.isEqual(data2)
    }
    
    private func currentDrawing() -> Drawing {
        return Drawing(stroke: self.mainImageView.image, background: self.backgroundImageView.image)
    }
    
