selectable.go
func (s *selectable) FindByID(id string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.ID, id).Single())
}
func (s *selectable) FindByID(id string) *Selection {
	return newSelection(s.session, s.selectors.Append(target.ID, id).Single())
}
// FindByID finds exactly one element that has the given ID.