selectable.go
func (s *selectable) Find(selector string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.CSS, selector).Single())
}
func (s *selectable) Find(selector string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.CSS, selector).Single())
}
// Find finds exactly one element by CSS selector.