     }
 
     /// If contentSize.width is not over safe area, paging menu view applys cellAlignment to each the cells.
-    private func adjustAlignmentIfNeeded() {
+    private func alignContainerViewIfNeeded() {
         let safedViewWidth = bounds.width - contentSafeAreaInsets.horizontal
         let hasScrollableArea = safedViewWidth < contentSize.width
         

        case type(type: PagingMenuViewCell.Type)
    }
    
    /// If contentSize.width is not over safe area, paging menu view applys this value to each the cells.
    ///
    /// - center: centering each PagingMenuViewCell object.
    /// - left: aligning each PagingMenuViewCell object on the left side.

        contentSize = CGSize(width: containerWidth, height: bounds.height)
        containerView.frame = CGRect(origin: .zero, size: contentSize)

        alignContainerViewIfNeeded()
        alignEachVisibleCell()
    }
    
    public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
