public static async void PersonReadyToGo(Person person)
        {
            // ready seconds

            await Task.Run(() =>
            {
                int intReadySecs = GetSeconds(person.ReadyTimeInterval);
                Thread.Sleep(person.ReadyTimeInterval);
                Console.WriteLine($"{person.FamilyTitle} gets ready in {intReadySecs} secs.");
                ReadyToGo.MorningPassengerCount += 1;
                ReadyToGo.ArePassengersReadyToGoYet();
            });
        }
        // Note: Asynchronously runs when you DON'T return value as a Task in signature.
        public static async void MomGetsReady()
        {
            // ready seconds
            int intReadyTimeInterval = 2000;
            int intReadySecs         = GetSeconds(intReadyTimeInterval);

            await Task.Run(() =>
            {
                Thread.Sleep(intReadyTimeInterval);
                Console.WriteLine($"Mom gets ready in {intReadySecs} secs.");
                ReadyToGo.MorningPassengerCount += 1;
                ReadyToGo.ArePassengersReadyToGoYet();
            });
        }