class Warning implements Serializable, Comparable<Warning> {

  @Override
  public boolean equals(@Nullable Object o) {
    if (this == o) {
      return true;
    } else if (!(o instanceof Warning)) {
      return false;
    }
    Warning w = (Warning) o;
    return _text.equals(w._text) && Objects.equals(_tag, w._tag);
  }

  public  Warning(String text, @Nullable String tag);

}