public function cleanDate($date)
    {
        $response = $this->query($this->prepareUri('clean/birthdate'), [$date]);
        $result = $this->populate(new Date, $response);
        if (!$result instanceof Date) {
            throw new RuntimeException('Unexpected populate result: ' . get_class($result). '. Expected: ' . Date::class);
        }

        return $result;
    }