private function createCache(array $cache)
    {
        ksort($cache);

        $format = "\t%s => %s," . PHP_EOL;
        $rows = [];

        foreach ($cache as $key => $value) {
            $rows[] = sprintf($format, var_export($key, true), var_export($value, true));
        }

        return sprintf('<?php return [%s];' . PHP_EOL, PHP_EOL . implode('', $rows));
    }