static void Main(string[] args)
        {
            Console.Write("Enter the First Name to Search:");
            string name = Console.ReadLine();
            //var repo = new CustomerRepository(CustomerData.Customers);
            //repo.FindByFirstName(name);
            //repo.FindCustomerByIntegerFields((a, b) => { return a == b; }, 1);
            //repo.FindCustomerByStringFields((a, b) => { return a == b; }, name);
            //repo.FindCustomerByFuncDelegate(customer=>customer.Id==1);
            //repo.FindCustomerByFuncDelegate(customer => customer.FirstName == name);
            //repo.FindCustomerByFuncDelegate(customer => customer.FirstName == name || customer.LastName==name);
            //repo.CheckCustomerExists(customer => customer.FirstName == name || customer.LastName == name);
            var dupCustomers = new List <Customer>();
            //repo.AddCustomerIfExists(customer => customer.FirstName == name,(a)=>dupCustomers.Add(a));

            var repoGenericsCustomer = new GenericRepository <Customer>(CustomerData.Customers);

            repoGenericsCustomer.CheckCustomerExists(customer => customer.FirstName == name || customer.LastName == name);
            repoGenericsCustomer.AddCustomerIfExists(customer => customer.FirstName == name, (a) => dupCustomers.Add(a));
            var repoGenericsEmployee = new GenericRepository <Employee>(EmloyeeData.Employees);

            repoGenericsEmployee.CheckCustomerExists(employee => employee.FirstName == name || employee.LastName == name);
            var dupEmployees = new List <Employee>();

            repoGenericsEmployee.AddCustomerIfExists(employee => employee.FirstName == name, (a) => dupEmployees.Add(a));
        }