else { event.list().add(newComponent); }
  public MutableEvent add(Object obj) {    Sexp newComponent = (Sexp)obj;    if (event == null)      event = newComponent;    else if (event.isSymbol()) {      SexpList newEvent = new SexpList().add(event).add(newComponent);      event = newEvent;    }    else {      event.list().add(newComponent);    }    return this;  }