code: func (vs *ValueMap) Iter(iter func(Value, Value) bool) bool {
  	if vs == nil {
  		return false
  	}
  	return vs.hashMap.Iter(func(kt, vt util.T) bool {
  		k := kt.(Value)
  		v := vt.(Value)
  		return iter(k, v)
  	})
  }
docs: // Iter calls the iter function for each key/value pair in the map. If the iter
  // function returns true, iteration stops.