let snCollectionViewLayout = SNCollectionViewLayout()
       snCollectionViewLayout.fixedDivisionCount = 4 // Columns for .vertical, rows for .horizontal
       snCollectionViewLayout.delegate = self
       myCollectionView.collectionViewLayout = snCollectionViewLayout

  // scale for items based number of columns
  func scaleForItem(inCollectionView collectionView: UICollectionView, withLayout layout: UICollectionViewLayout, atIndexPath indexPath: IndexPath) -> UInt {
        if indexPath.row == 0 || indexPath.row == 3 || indexPath.row == 10 || indexPath.row == 70 {
            
            return 2 
        }
        return 1
    }
    // height for item if set fixedDimension  height equal width
    func itemFlexibleDimension(inCollectionView collectionView: UICollectionView, withLayout layout: UICollectionViewLayout, fixedDimension: CGFloat) -> CGFloat {
        return fixedDimension
    }
    
    // header height
    func headerFlexibleDimension(inCollectionView collectionView: UICollectionView, withLayout layout: UICollectionViewLayout, fixedDimension: CGFloat) -> CGFloat {
        return 0
    }