public void Peek_Test()
{
IQueue <char> queue = new QueueViaLinkedList <char>(5);
queue.Enqueue('A');
queue.Enqueue('B');
queue.Enqueue('C');
queue.Enqueue('D');
queue.Enqueue('E');
queue.IsEmpty.Should().BeFalse();
queue.IsFull.Should().BeTrue();
queue.Count.Should().Be(5);
queue.Peek().Should().Be('A');
queue.Peek().Should().Be('A');
queue.Peek().Should().Be('A');
Action act = () => new QueueViaLinkedList <char>(5).Peek();
act.Should().Throw <IndexOutOfRangeException>()
.WithMessage("Queue is empty.");
}
static void Main(string[] args)
{
QueueViaLinkedList <int> queue = new QueueViaLinkedList <int>();
int i = 9;
queue.Enqueue(i);
queue.Enqueue(i * 3);
queue.Enqueue(i * 6);
Console.WriteLine(queue.Peek());
Console.WriteLine(queue.Dequeue());
}