firePropertyChange(PROTOTYPE_CELL_VALUE_PROPERTY_CHANGED, old, obj);
firePropertyChange("prototypeCellValue", old, obj);
  public void setPrototypeCellValue(Object obj)  {    Object old = prototypeCellValue;    Component comp = getCellRenderer()      .getListCellRendererComponent(this, obj, 0, false, false);     Dimension d = comp.getPreferredSize();    fixedCellWidth = d.width;    fixedCellHeight = d.height;    prototypeCellValue = obj;    firePropertyChange(PROTOTYPE_CELL_VALUE_PROPERTY_CHANGED, old, obj);  }