static function getAlreadyUsedExecutionTime($slts_id)
{
global $DB;
$result = array();
$query = "SELECT DISTINCT `execution_time`\n FROM `glpi_slalevels`\n WHERE `slts_id` = '{$slts_id}';";
foreach ($DB->request($query) as $data) {
$result[$data['execution_time']] = $data['execution_time'];
}
return $result;
}