queue.go
func (q *Queue) Length() uint {
	q.key.RLock()
	defer q.key.RUnlock()
	if nil == q.underlyer {
		return 0
	}
	return q.underlyer.length
}
func (q *Queue) Length() uint {
	q.key.RLock()
	defer q.key.RUnlock()
	if nil == q.underlyer {
		return 0
	}
	return q.underlyer.length
}
func ( q * Queue ) Length ( ) uint { q . key . RLock ( ) defer q . key . RUnlock ( ) if nil == q . underlyer { return 0 } return q . underlyer . length }
// Length returns the number of items in the Queue.
Length returns the number of items in the Queue .