public void ShouldNotifyListeners()
{
//Arrange
var user1 = new User1();
var user2 = new User2();
videoCreator.RegisterListener(user1);
videoCreator.RegisterListener(user2);
//Act
videoCreator.NewVideoAdd(new MyYoutubeChannel {
Id = 4, VideoLink = "part4"
});
//Assert
user1.IsReceived.Should().BeTrue();
user2.IsReceived.Should().BeTrue();
}