queue.go
func (queue *queue) Peek() interface{} {
	if queue.size == 0 {
		return nil
	}
	return queue.elements[queue.start%int64(queue.cap)]
}
func (queue *queue) Peek() interface{} {
	if queue.size == 0 {
		return nil
	}
	return queue.elements[queue.start%int64(queue.cap)]
}
func ( queue * queue ) Peek ( ) interface { } { if queue . size == 0 { return nil } return queue . elements [ queue . start % int64 ( queue . cap ) ] }
// Peek returns the element at the front of the queue.
Peek returns the element at the front of the queue .