UIContextualActionHandler actionHandler; // = ...
UICollectionLayoutListConfiguration *listConfig = [[UICollectionLayoutListConfiguration alloc] initWithAppearance: UICollectionLayoutListAppearanceInsetGrouped];
[listConfig setTrailingSwipeActionsConfigurationProvider:^UISwipeActionsConfiguration* (NSIndexPath *indexPath) {
    UIContextualAction *action = [UIContextualAction contextualActionWithStyle:UIContextualActionStyleNormal
                                                                         title:@"Done!"
                                                                       handler:actionHandler];
    return [UISwipeActionsConfiguration configurationWithActions:@[action]];
}];