SushiBarBase/SushiBar/SushiBarListImplement/DataListSingleton.cs

using SushiBarListImplement.Models;

namespace SushiBarListImplement
{
    public class DataListSingleton
    {
        private static DataListSingleton _instance;
        public List<Component> Components { get; set; }
        public List<Order> Orders { get; set; }
        public List<Sushi> Sushis { get; set; }
        public List<Client> Clients { get; set; }
        private DataListSingleton()
        {
            Components = new List<Component>();
            Orders = new List<Order>();
            Sushis = new List<Sushi>();
            Clients = new List<Client>();
        }

        public static DataListSingleton GetInstance()
        {
            if (_instance == null)
            {
                _instance = new DataListSingleton();
            }
            return _instance;
        }
    }
}