@Override
    public String toString() {
      StringBuilder builder = new StringBuilder();
      String[] args = getExecString();
      for (String s : args) {
        if (s.indexOf(' ') >= 0) {
          builder.append('"').append(s).append('"');
        } else {
          builder.append(s);
        }
        builder.append(' ');
      }
      return builder.toString();
    }