code: func (a *Args) PeekMulti(key string) [][]byte {
  	var values [][]byte
  	a.VisitAll(func(k, v []byte) {
  		if string(k) == key {
  			values = append(values, v)
  		}
  	})
  	return values
  }
docs: // PeekMulti returns all the arg values for the given key.