/**
* @param string $class_name Class name of table to query
* @param string $sort_by Sort by column
* @param Direction $direction Assumes ascending if omitted
* @param int $start Start index (inclusive), null/0 for beginning of set
* @param int $end Stop index (inclusive), null/-1 for end of set, -2 for penultimate record
*/
public function __construct($class_name, $sort_by, Direction $direction = null, $start = null, $end = null)
{
parent::__construct($class_name, null, $sort_by, $direction, $start, $end);
}