public async Task AddMessageReturns503IfStorageUnavailable()
        {
            mockStore.Setup(store => store.AddMessage(It.IsAny <string>(), It.IsAny <Message>()))
            .ThrowsAsync(new StorageUnavailableException("Storage is unavailable!"));
            var messageDto = new AddMessageDto("Hi!", "amansour");

            TestUtils.AssertStatusCode(HttpStatusCode.ServiceUnavailable, await myController.Post("amansour_nbilal", messageDto));
        }