code: func (s *Set) Items() []interface{} {
  	s.RLock()
  	defer s.RUnlock()
  	items := make([]interface{}, len(s.m))
  	i := 0
  	for k := range s.m {
  		items[i] = k
  		i++
  	}
  	return items
  }
docs: // Items returns a slice of all items in the set.
  // Modification to the returned slice does not affect the structure of
  // the set. However, any item in the set that is a pointer will be affected
  // if modified.