skl/skl.go
func (s *Iterator) Next() {
	y.AssertTrue(s.Valid())
	s.n = s.list.getNext(s.n, 0)
}
func (s *Iterator) Next() {
	y.AssertTrue(s.Valid())
	s.n = s.list.getNext(s.n, 0)
}
func ( s * Iterator ) Next ( ) { y . AssertTrue ( s . Valid ( ) ) s . n = s . list . getNext ( s . n , 0 ) }
// Next advances to the next position.
Next advances to the next position .