public async Task <bool> Handle(MoveInCommand message, CancellationToken cancellationToken)
        {
            // Add/Update the Buyer AggregateRoot
            // DDD patterns comment: Add child entities and value-objects through the Order Aggregate-Root
            // methods and constructor so validations, invariants and business logic
            // make sure that consistency is preserved across the whole aggregate
            Flat flat = new Flat(message.flatNo);

            flat.MoveIn(message.List);

            _flatRepository.Add(flat);

            return(await _flatRepository
                   .SaveEntitiesAsync());
        }