/// <summary>
        /// method, using switch-case for choosing needed methods
        /// </summary>
        /// <param name="name"></param>
        public CommandSelection(string name, string name2)
        {
            ReaderFromXML readerFromXML = new ReaderFromXML();
            Invoker       invoker       = new Invoker();
            HandlerCars   handlerCars   = new HandlerCars(@"C:\Users\user\source\repos\TAT-2019.1\Task6\" + name,
                                                          @"C:\Users\user\source\repos\TAT-2019.1\Task6\" + name2);

            Console.WriteLine("Select command (1-5): \n 1.Count car brands \n 2.Count all cars \n " +
                              "3.Average car price \n 4.Average price type \n 5.Clear console \n 6.Execute \n 7.Exit");
            string selection = Console.ReadLine();

            while ((selection = Console.ReadLine().ToLower()) != "6")
            {
                switch (selection)
                {
                case "1":
                    invoker.SetCommand(new AmountOfCars(handlerCars));
                    invoker.StartMethod();
                    break;

                case "2":
                    invoker.SetCommand(new TypesOfAllBrands(handlerCars));
                    invoker.StartMethod();
                    break;

                case "3":
                    invoker.SetCommand(new AveragePriceOfCar(handlerCars));
                    invoker.StartMethod();
                    break;

                case "4":
                    invoker.SetCommand(new AveragePriceOfCarEveryBrand(handlerCars));
                    invoker.StartMethod();
                    break;

                case "5":
                    Console.Clear();
                    readerFromXML.Read("Cars.xml", "Trucks.xml");
                    break;

                case "6":
                    invoker = null;
                    continue;

                //  break;
                case "7":
                    break;

                default:
                    Console.WriteLine("Chose number only from 1 to 6");
                    break;
                }
                ExecuteCommands += invoker.StartMethod;
            }
            ExecuteCommands?.Invoke();
        }
 /// <summary>
 /// constructor
 /// </summary>
 /// <param name="handler"></param>
 public AveragePriceOfCarEveryBrand(HandlerCars handler)
 {
     this.handlercars = handler;
 }