code: func (s *SyncedSet) Contains(datas ...interface{}) bool {
  	s.RLock()
  	defer s.RUnlock()
  	for _, data := range datas {
  		if _, ok := s.set[data]; !ok {
  			return false
  		}
  	}
  	return true
  }
docs: // Contains returns true if the syncedset contains all the data