adjustVisibility(this);
  void setDotImpl(int dot)  {    if (dot >= 0)      {        Document doc = textComponent.getDocument();        if (doc != null)          this.dot = Math.min(dot, doc.getLength());        this.dot = Math.max(this.dot, 0);        this.mark = this.dot;                clearHighlight();                appear();                adjustVisibility(this);      }  }