saveUserSuspendCoroutine.kt

suspend fun saveUsername(username: String) {

    val result = suspendedSaveUsername(username)        
    handleResult(result)
}

suspend fun suspendedSaveUsername(username: String) = suspendCoroutine<String> { continuation ->

    StorageService.getInstance().saveUsername(username) { result ->
        continuation.resume(result)
    }
}