firePropertyChange(HEADER_RENDERER_PROPERTY, oldRenderer, headerRenderer);
changeSupport.firePropertyChange(HEADER_RENDERER_PROPERTY, oldRenderer, headerRenderer);
  public void setHeaderRenderer(TableCellRenderer renderer)  {    if (headerRenderer == renderer)      return;        TableCellRenderer oldRenderer = headerRenderer;    headerRenderer = renderer;    firePropertyChange(HEADER_RENDERER_PROPERTY, 		       oldRenderer, headerRenderer);  }