code: func (i *smallIndex) Val(id uint32) ([]byte, bool) {
  	i.mut.Lock()
  	val, ok := i.id2val[id]
  	i.mut.Unlock()
  	if !ok {
  		return nil, false
  	}
  
  	return []byte(val), true
  }
docs: // Val returns the value for the given index number, or (nil, false) if there
  // is no such index number.