         self.quietChanges {
 			self.digest=String(describing: decoder.decodeObject(of: NSString.self, forKey: "digest")! as NSString)
 			self.rank=decoder.decodeInteger(forKey:"rank") 
-			self.bookmarkData=decoder.decodeObject(of: NSData.self, forKey:"bookmarkData") as Data?
 			self.startsAt=decoder.decodeInteger(forKey:"startsAt") 
 			self.size=decoder.decodeInteger(forKey:"size") 
 			self.priority=decoder.decodeInteger(forKey:"priority") 

        super.encode(with:coder)
		coder.encode(self.digest,forKey:"digest")
		coder.encode(self.rank,forKey:"rank")
		if let bookmarkData = self.bookmarkData {
			coder.encode(bookmarkData,forKey:"bookmarkData")
		}
		coder.encode(self.startsAt,forKey:"startsAt")
		coder.encode(self.size,forKey:"size")
		coder.encode(self.priority,forKey:"priority")

            case "rank":
                if let casted=value as? Int{
                    self.rank=casted
                }
            case "startsAt":
                if let casted=value as? Int{
