NotificationService.kt

// creating a wrapper around static method
@Component
class MessageWrapper {
    fun creator(phoneNumber: PhoneNumber, messageServiceSid: String, text: String) =
            Message.creator(phoneNumber, messageServiceSid, text)
}

@Service
class NotificationService(
        private val restClient: TwilioRestClient,
        private val secretRepository: SecretRepository,
        // Inject the wrapper
        private val messageWrapper: MessageWrapper
) {
    fun notify(notificationRequest: NotificationRequest): NotificationResponse {
        val (countryCode, phoneNumber, text) = notificationRequest
        val messagingServiceId = secretRepository.getTwilloMessagingServiceId()

        // Using wrapper
        val messageCreator = messageWrapper.creator(
                PhoneNumber(countryCode + phoneNumber),
                messagingServiceId,
                text)

        val message = messageCreator.create(restClient)

        return when (message.status){
            Message.Status.FAILED ->
                    NotificationFailed(
                            message.errorCode,
                            message.errorMessage)
            else ->
                    NotificationSuccess
        }
    }
}