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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 certificate_rabbitmq(self):
 """ Gets the Certificate RabbitMQ API client. Returns: CertificateRabbitMQ: """

        if not self.__certificate_rabbitmq:
            self.__certificate_rabbitmq = CertificateRabbitMQ(self.__connection)
        return self.__certificate_rabbitmq