public function getRootFamilies()
    {
        $root = [];
        foreach ($this->getFamilies() as $family) {
            if ($family->isInstantiable()) {
                $p = $family->getParent();
                if (!$p || ($p && !$p->isInstantiable())) {
                    $root[$family->getCode()] = $family;
                }
            }
        }

        return $root;
    }