private function randomName($parent)
    {
        // UUIDs are a pre-existing library dependency, so we'll use that instead
        // of adding random_compat or something similar.
        // Generate a UUID, then strip `-` and trim to expected length.
        // @todo revisit once library requires php >= 7.0 and random_int() can be used without dependency.
        $rand = substr(str_replace('-', '', Uuid::uuid4()), 0, 20);

        return $this->childPath($parent, $rand);
    }