public void TestConcreteSubscriber()
{
string name = "concrete subscriber";
string data = "test data";
var messageBrokerMock = new Mock <MessageBroker>();
var subscriber = new ConcreteSubscriber(name, messageBrokerMock.Object);
subscriber.EnqueueData(data);
Assert.AreEqual(name + "'s Data : \r\n" + data + "\r\n", subscriber.GetDisplayData());
}