Adjust insets of a specific section in UICollectionView

You must have to implement UICollectionViewDelegateFlowLayout to your class with this method:

For Swift 4

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {

    var edgeInsets = UIEdgeInsets()
    if section == THE_SECTION_YOU_WANT {
        // edgeInsets configuration stuff
    }

    return edgeInsets;
}

For Swift 3

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAtIndex section: Int) -> UIEdgeInsets {

    var edgeInsets = UIEdgeInsets()
    if section == THE_SECTION_YOU_WANT {
        // edgeInsets configuration stuff
    }

    return edgeInsets;

}