Devise\Pages\PageVersionManager::copyFieldsFromVersionToVersion PHP Method

    protected function copyFieldsFromVersionToVersion($oldVersion, $newVersion)
    {
        foreach ($oldVersion->fields as $field) {
            $this->Field->create(["collection_instance_id" => $field->collection_instance_id, "page_version_id" => $newVersion->id, "type" => $field->type, "human_name" => $field->human_name, "key" => $field->key, "json_value" => $field->json_value]);
        }
    }