func (stack *Stack) Push(entry interface{}) {
	stack.key.Lock()
	defer stack.key.Unlock()

	if nil == stack.underlyer {
		stack.underlyer = NewLinkedList()
	}
	stack.underlyer.AddFront(entry)
}
func (stack *Stack) Push(entry interface{}) {
	stack.key.Lock()
	defer stack.key.Unlock()

	if nil == stack.underlyer {
		stack.underlyer = NewLinkedList()
	}
	stack.underlyer.AddFront(entry)
}
func ( stack * Stack ) Push ( entry interface { } ) { stack . key . Lock ( ) defer stack . key . Unlock ( ) if nil == stack . underlyer { stack . underlyer = NewLinkedList ( ) } stack . underlyer . AddFront ( entry ) }
// Push adds an entry to the top of the Stack.
Push adds an entry to the top of the Stack .