protected function libUniqueId()
{
static $id;
if (!isset($id)) {
$id = mt_rand(0, pow(36, 8));
}
$id += mt_rand(0, 10) + 1;
return [Type::T_STRING, '', ['u' . str_pad(base_convert($id, 10, 36), 8, '0', STR_PAD_LEFT)]];
}