void clearTable() {
      int num_rows = table.getRowCount();

      if (num_rows > 0) {
        for (int i = 0; i < num_rows; i++) table_model.removeRow(0);
        table_model.fireTableRowsDeleted(0, num_rows - 1);
        repaint();
      }
    }
 public void clearData() {
   int size = getRowCount();
   objects.clear();
   super.fireTableRowsDeleted(0, size);
 }
 @Override
 public void fireTableRowsDeleted(int firstRow, int lastRow) {
   // logger.info("fireTableRowsDeleted("+firstRow+","+lastRow+")");
   super.fireTableRowsDeleted(firstRow, lastRow);
 }
 @Override
 public void fireTableRowsDeleted(int firstRow, int lastRow) {
   super.fireTableRowsDeleted(firstRow, lastRow);
 }