public MainWindow()
        {
            InitializeComponent();

            // Set Sources
            _tickets = TicketManager.GetTickets();
            TicketListView.ItemsSource = _tickets;

            _finances = FinanceManager.GetFinances();
            FinancesListView.ItemsSource = _finances;

            _businesses = CustomerManager.GetCustomers();
            BussinessListView.ItemsSource = _businesses;

            _techs = TechnicianManager.GetTechnicians();
            TechListView.ItemsSource = _techs;
        }