public function propertiesIdents()
    {
        $metadata = $this->proto()->metadata();
        if (isset($metadata['admin']['lists'])) {
            $adminMetadata   = $metadata['admin'];
            $collectionIdent = $this->collectionIdent();
            if (isset($adminMetadata['lists'][$collectionIdent]['properties'])) {
                return $adminMetadata['lists'][$collectionIdent]['properties'];
            }
        }

        return [];
    }