 
         cachedPath.append(belzierPath.copy() as! UIBezierPath)
         cacheIndex = cachedPath.count
-//        print("cacheIndex \(cacheIndex)")
     }
 
 }

        cacheIndex -= 1
      }

//      print("cacheIndex undo \(cacheIndex)")

      cacheIndex -= 1

      if cacheIndex < 0 {

      if cachedPath.count - 1 < cacheIndex {
        return
      }

      currentPath = cachedPath[cacheIndex]
      _signature = nil
      self.redraw()
