/**
* Get the locktime for this grade.
*
* @return int $locktime timestamp for lock to activate
*/
public function get_locktime()
{
$this->load_grade_item();
$item_locktime = $this->grade_item->get_locktime();
if (empty($this->locktime) or $item_locktime and $item_locktime < $this->locktime) {
return $item_locktime;
} else {
return $this->locktime;
}
}
