public static function configMerge() {
        $result = array();
        $args = func_get_args();
        foreach ($args as $arg) {
            if (!is_array($arg)) {
                continue;
            }
            foreach ($arg as $key => $value) {
                if (is_numeric($key)) {
                    // Renumber numeric keys as array_merge() does.
                    $result[] = $value;
                } elseif (array_key_exists($key, $result) && is_array($result[$key]) && is_array($value)) {
                    // Recurse only when both values are arrays.
                    $result[$key] = ConfigServiceProvider::configMerge($result[$key], $value);
                } else {
                    // Otherwise, use the latter value.
                    $result[$key] = $value;
                }
            }
        }
        return $result;
    }