public static PrecomputedTableManager getInstance(Database database) throws SQLException {
public static PrecomputedTableManager getInstance(Connection conn) throws SQLException {
    public static PrecomputedTableManager getInstance(Database database) throws SQLException {        synchronized (instances) {            if (!(instances.containsKey(database))) {                instances.put(database, new PrecomputedTableManager(database));            }        }        return (PrecomputedTableManager) instances.get(database);    }