NSIndexSet in swift3

hi ,

dose any one know how to write code **** in swift ?

[tableView reloadSections:[NSIndexSet indexSetWithIndex:1] withRowAnimation:UITableViewRowAnimationAutomatic];

I wrote like this.

tableView.reloadSections(NSIndexSet(index: 1) as IndexSet, with: UITableViewRowAnimation.automatic)

but, looks something strange..