Workgroup::getSprintDurationDefaultKey

static function getSprintDurationDefaultKey()
{
	$list = static::getSprintDurationList();
	$result = array_key_first($list);
	foreach ($list as $key => $item)
	{
		if (
			isset($item['DEFAULT'])
			&& $item['DEFAULT'] === true
		)
		{
			$result = $key;
			break;
		}
	}

	return $result;
}