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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def vehicle_registration_code(self, locale: Optional[str] = None) -> str: """Get vehicle registration code of country. :param locale: Registration code for locale (country). :return: Vehicle registration code. """

        if locale:
            return VRC_BY_LOCALES[locale]

        return self.random.choice(VR_CODES)