@Override
  public Integer getMaxLineNumber(@NotNull Editor editor) {
    for (int i = editor.getDocument().getLineCount(); i > 0; i--) {
      Integer number = convertImpl(i, false);
      if (number != null) {
        return number;
      }
    }
    return 0;
  }
@Override
  public Integer getMaxLineNumber(@NotNull Editor editor)