如何扩展水平滚动收集视图，将单元格保持在屏幕中央？

Question

我对此代码有疑问。我需要将水平滚动集合视图从屏幕的边缘扩展到边缘，以使主单元格显示在屏幕中央，并显示前一个和下一个单元格，但是我不知道该怎么做，我在网上找不到任何东西。 This is the problem

class ViewController: UIViewController {
            view.addSubview(collectionView)
                    collectionView.backgroundColor = .clear
                    collectionView.topAnchor.constraint(equalTo:                    view.safeAreaLayoutGuide.topAnchor, constant: 80).isActive = true
                    collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 50).isActive = true
                    collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -50).isActive = true
                    collectionView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -70).isActive = true
                    collectionView.isPagingEnabled = true
                    collectionView.showsHorizontalScrollIndicator = false
                    collectionView.showsVerticalScrollIndicator = false
                    collectionView.delegate = self
                    collectionView.dataSource = self
                    collectionView.register(CustomCell.self.forCellWithReuseIdentifier: "cellId") 
        }
    }

     extension ViewController: UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

        func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
            return CGSize(width: collectionView.frame.width - 10, height: collectionView.frame.width * 1.6)
        }

        func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
            return CategoriesViewController.defaultQuotes.count
        }

        func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath) as! CustomCell
            cell.data = CategoriesViewController.defaultQuotes[indexPath.row]
            return cell
        }
    }

    class CustomCell: UICollectionViewCell {

        var data:CustomData? {
            didSet {
                guard let data = data else { return }
                //bg.image = data.image
                text.text = data.title
                authorLabel.text = "- " + data.author
            }
        }

        fileprivate let text: UILabel = {
                    let quote = UILabel()
            quote.textAlignment = .center
            quote.translatesAutoresizingMaskIntoConstraints = false
            return quote
        }()

        fileprivate let container: UIImageView = {
            let view = UIImageView()
            view.image = BackgroundImages.images[0]
            return view
        }()

        func setUpViews() {
            contentView.addSubview(container)
            container.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
            container.leadingAnchor.constraint(equalTo: contentView.leadingAnchor).isActive = true
            container.trailingAnchor.constraint(equalTo: contentView.trailingAnchor).isActive = true
            container.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true

            contentView.addSubview(text)
            text.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 25).isActive = true
            text.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 25).isActive = true
            text.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -25).isActive = true
            text.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -25).isActive = true

        override init(frame: CGRect) {
        super.init(frame: frame)
            setUpViews()
        }

        required init?(coder aDecoder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
    }