if (col == -1){ return; }
        public void mousePressed(MouseEvent e) {            if (e.getButton() != MouseEvent.BUTTON1) {                return;            }            int col = header.columnAtPoint(e.getPoint());            TableColumn pressedColumn = searchResultTable.getColumnModel().                getColumn(col);            renderer.setPressedColumn(col);            renderer.setSelectedColumn(col);            header.repaint();            if (header.getTable().isEditing()) {                header.getTable().getCellEditor().stopCellEditing();            }            boolean isAscent;            if (SortButtonRenderer.UP == renderer.getState(col)) {                isAscent = true;            }            else {                isAscent = false;            }            SearchNode rootNode = ( (SearchNode) tableModel.                                   getRoot());            if (pressedColumn == tableColumns[0]) {                rootNode.setSortCriteria(SearchNode.SORT_FILENAME,                                         isAscent);            }            else if (pressedColumn == tableColumns[1]) {                rootNode.setSortCriteria(SearchNode.SORT_GROESSE,                                         isAscent);            }            else if (pressedColumn == tableColumns[2]) {                rootNode.setSortCriteria(SearchNode.SORT_ANZAHL,                                         isAscent);            }            searchResultTable.updateUI();        }