designPattern/DesignPattern/Strategy/Checkout.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Strategy
{
    internal class Checkout
    {
        public IPayment Payment { get; set; }

        public Checkout(IPayment payment)
        {
            Payment = payment;
        }

        public void Charge(int total)
        {
            Console.WriteLine($"Charging {total}");
            this.Payment.Pay(total);
        }
    }
}