public AgentRepository(IEventBus eventBus, IPersister persister, ILogger <AgentRepository> logger)
        {
            _eventBus  = eventBus;
            _persister = persister;
            _logger    = logger;

            _agents = _persister.LoadCollection <Agent>(FILENAME).ToList();
        }
        public ProductRepository(IEventBus eventBus, IPersister persister,
                                 IAgentRepository agentRepo,
                                 ILogger <ProductRepository> logger)
        {
            _eventBus  = eventBus;
            _persister = persister;
            _agentRepo = agentRepo;
            _logger    = logger;

            _products = _persister.LoadCollection <Product>(FILENAME).ToList();

            FillupRelations();
        }