ScrollToSection.swift

    func scrollToSection(_ section: Int)  {
        
        let numbersOfBehaviors = items[section].behaviors?.count
        
        if let cv = self.collectionView {
            let indexPath = IndexPath.init(item: 1, section: section)
            if let attributes =  cv.layoutAttributesForSupplementaryElement(ofKind: UICollectionElementKindSectionHeader, at: indexPath) {
                
                let topOfHeader = CGPoint(x: 0, y: attributes.frame.origin.y - cv.contentInset.top)
                cv.setContentOffset(topOfHeader, animated:true)
            }
        }
    }