public function add($type, $subtype, $class = "")
{
$id = $this->getId($type, $subtype);
if ($id) {
return $id;
}
$this->iterator++;
$id = $this->iterator;
$this->subtypes[$id] = ['type' => $type, 'subtype' => $subtype, 'class' => $class];
return $id;
}