public async Task GetOldMessagesAsync_Test()
        {
            //Arrage:
            await InitDictDataAsync();

            var service = new ConversationMsgAppService(statefulServiceContext, stateManager);
            var msg2    = DefaultConversationMsg2.DeepCopy();
            var msg1    = DefaultConversationMsg.DeepCopy();

            //Act:
            var oldMeesage = await service.GetOldMessagesAsync(new GetOldMessagesInput()
            {
                Id          = msg2.ConversationId,
                OldestMsgId = msg2.Id,
            });

            //Assert:
            Assert.AreEqual(1, oldMeesage.Count);
        }