Sample for callback returning from flow

completeCallback.kt

   fun readMessage(dialog: QBChatDialog): Flow<ArrayList<QBChatMessage>> {
        val historyDeferred = CompletableDeferred<ArrayList<QBChatMessage>>()
        chatHelper.ReadChatHistory(dialog, object : QBEntityCallback<ArrayList<QBChatMessage>> {
            override fun onSuccess(listmessage: ArrayList<QBChatMessage>?, p1: Bundle?) {
                historyDeferred.complete(listmessage ?: arrayListOf())
            }

            override fun onError(p0: QBResponseException?) {
                historyDeferred.completeExceptionally(p0 ?: CancellationException())
            }
        })
        return flow {
            try {
                emit(historyDeferred.await())
            } catch (e: Exception) {
                Log.e(TAG, "Reading Message Exceptionn: $e")
            }
        }
    }