sclass MsgOut extends DynamicObject {
  S buttonsIntro;
  LS buttons;
  S placeholder;
  S defaultInput;
  
  bool isEmpty() { ret empty(buttons); }
}

sclass Msg extends DynamicObject {
  long time;
  bool fromUser;
  S text;
  MsgOut out;
  
  *() {}
  *(bool *fromUser, S *text) { time = now(); }
  
  toString {
    ret "[" + time + "] " + (fromUser ? "User" : "Bot") + ": " + text;
  }
}