etcdserver/api/v2store/store.go
func (s *store) Index() uint64 {
	s.worldLock.RLock()
	defer s.worldLock.RUnlock()
	return s.CurrentIndex
}
func (s *store) Index() uint64 {
	s.worldLock.RLock()
	defer s.worldLock.RUnlock()
	return s.CurrentIndex
}
// Index retrieves the current index of the store.