private function initIndices(SearchableInterface $searchableModel)
    {
        $indexNames = $searchableModel->getIndices();

        return \array_map(function ($indexName) {
            if ($this->env !== null) {
                $indexName = $this->env . '_' . $indexName;
            }

            return $this->initIndex($indexName);
        }, $indexNames);
    }