protected function serializeEmbedOne(EmbedMetadata $embedMeta, Embed $embed = null)
    {
        if (null === $embed) {
            return;
        }
        $serialized = [];
        foreach ($embedMeta->getAttributes() as $key => $attrMeta) {
            $serialized[$key] = $this->serializeAttribute($embed->get($key), $attrMeta);
        }
        foreach ($embedMeta->getEmbeds() as $key => $embeddedPropMeta) {
            $serialized[$key] = $this->serializeEmbed($embed->get($key), $embeddedPropMeta);
        }

        return empty($serialized) ? null : $serialized;
    }