Removes the first item from the queue and returns it as an Object
Dequeue removes the item at the beginning of the queue and decrements the Count property by one.
The Dequeue method generates an error if applied to an empty queue. Thus, it may be advisable to check for an empty queue using the Count property before attempting to dequeue.
Dequeue is similar to the Peek method. The Peek method returns a reference to the object at the beginning of the queue, but unlike the Dequeue method, does not remove it from the queue.