如何在一行收集视图中设置不同的高度和宽度的单元格

Question

我想实现这一目标： Ideal

但这是到目前为止我得到的： now

这是我现在拥有的代码：

extension Profile_PhotosUpload: UICollectionViewDelegateFlowLayout{

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let bigSize = CGSize(width: 180.0, height: 180.0)
    let smallSize = CGSize(width: 70, height: 70)
    if indexPath.row == 0{
        return bigSize
    }else{
        return smallSize
    }
}
// Horizontal Space
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
    return 5
}
// Vertical Space
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
    return 10
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    return UIEdgeInsets(top: -60, left: 0, bottom: 0, right: 0)
}

}

请有人帮忙。