private void MainMenu()
        {
            char item;

            do
            {
                item = ConsolePresenter.GetChar("What do you want?\n[1] Buy our product\n[2] Check our warehouse state\n[3] Add new product\n[4] Leave\nDecision: ");
                ConsolePresenter.ClearConsole();
            }while (item != '1' && item != '2' && item != '3' && item != '4');

            switch (item)
            {
            case '1':
                TradingConsole.Buy(Products);
                MainMenu();
                break;

            case '2':
                CheckingConsole.Check(Products);
                Leave();
                break;

            case '3':
                AddingConsole.Add(Products);
                MainMenu();
                break;

            case '4':
                Leave();
                break;
            }
        }
        public static void Buy(List <Product> products)
        {
            string toFind;

            Product foundItem;

            int count;

            do
            {
                toFind = ConsolePresenter.GetString("What do you want to buy (Enter \"QUIT\" for back to main menu): ");

                if (toFind == "QUIT")
                {
                    ConsolePresenter.ClearConsole();
                    return;
                }

                if (products.Exists(item => item.Name.Contains(toFind)) == false)
                {
                    ConsolePresenter.GetChar("No results found, press any key. ");
                    ConsolePresenter.ClearConsole();
                }
            }while (products.Exists(item => item.Name.Contains(toFind)) == false);

            foundItem = products.Find(item => item.Name.Contains(toFind));

            count = ConsolePresenter.GetInt("Quantity: ");

            while (foundItem.Count < count)
            {
                count = ConsolePresenter.GetInt($"Sorry, we have only {foundItem.Count}, insert new value or enter \"0\" for back to main menu: ");
                if (count == 0)
                {
                    ConsolePresenter.ClearConsole();
                    return;
                }
            }

            char answer;

            do
            {
                answer = ConsolePresenter.GetChar($"Do you want to buy {count} x {foundItem.Name}? It will cost {count * (foundItem.Price)}. [(Y)es] [(N)o] ");
                ConsolePresenter.ClearConsole();
            }while (answer != 'y' && answer != 'n' && answer != 'Y' && answer != 'N');

            if (answer == 'y' || answer == 'Y')
            {
                products.Find(item => item.Name.Contains(toFind)).Count = foundItem.Count - count;
            }
        }
        private void Leave()
        {
            char answer;

            do
            {
                answer = ConsolePresenter.GetChar("\nDo you want to leave shop? [(Y)es] [(N)o] ");
                ConsolePresenter.ClearConsole();
            }while (answer != 'y' && answer != 'n' && answer != 'Y' && answer != 'N');

            if (answer == 'y' || answer == 'Y')
            {
                return;
            }
            else
            {
                MainMenu();
            }
        }