static void Main(string[] args)
{
IMediator mediator = new MessageMediator();
int numberOfColleagues = 10;
List <IColleague> colleagues = new List <IColleague>();
for (int i = 0; i < numberOfColleagues; i++)
{
IColleague colleague = new ConcreteColleague($"Colleague-{i + 1}");
mediator.RegisterColleague(colleague);
colleagues.Add(colleague);
}
var random = new Random();
var senderIndex = random.Next(0, colleagues.Count);
var sender = colleagues[senderIndex] as ConcreteColleague;
sender.SendMessage("Test", Guid.NewGuid().ToString());
Console.ReadKey();
}