     guard case let dataSource as PaperOnboardingDataSource = self.dataSource else {
       fatalError("set dataSource")
     }
-    
+
     var items = [OnboardingItemInfo]()
     for index in 0..<itemsCount {
       let info = dataSource.onboardingItemAtIndex(index)

// MARK: public

public extension PaperOnboarding {
  
  func currentIndex(index: Int, animated: Bool) {
    if 0 ..< itemsCount ~= index {
      currentIndex = index
      if let postion = pageView?.positionItemIndex(index, onView: self) {
        fillAnimationView?.fillAnimation(bakcgroundColor(currentIndex), centerPosition: postion, duration: 0.5)
      }
      pageView?.currentIndex(index, animated: animated)
      contentView?.currentItem(index, animated: animated)
    }
    
  }
}
// MARK: create

extension PaperOnboarding {
  
  private func commonInit() {
    itemsInfo = createItemsInfo()
    translatesAutoresizingMaskIntoConstraints = false

    pageView = createPageView()
    gestureControl = GestureControl(view: self, delegate: self)
  }

  private func createPageView() -> PageView {
    let pageView = PageView.pageViewOnView(self,
                                          itemsCount: itemsCount,
