multiselection.go
func (s *MultiSelection) At(index int) *Selection {
	return newSelection(s.session, s.selectors.At(index))
}
func (s *MultiSelection) At(index int) *Selection {
	return newSelection(s.session, s.selectors.At(index))
}
// At finds an element at the provided index. It only applies to the immediate selection,
// meaning that the returned selection may still refer to multiple elements if any parent
// of the immediate selection is also a *MultiSelection.