/// <summary>
/// Remove an event handler.
/// </summary>
/// <param name="clock">Customer of event.</param>
public void Remove(ContraClock clock)
{
clock.ClockWorking -= MessageHandler;
Console.WriteLine($"{GetType()} unregistered.");
}
/// <summary>
/// Add an event handler.
/// </summary>
/// <param name="clock">Customer of event.</param>
public void Add(ContraClock clock)
{
clock.ClockWorking += MessageHandler;
Console.WriteLine($"{GetType()} registered.");
}