func (stack *Stack) IsEmpty() bool {
	stack.key.RLock()
	defer stack.key.RUnlock()
	return stack.underlyer == nil || stack.underlyer.IsEmpty()
}
func (stack *Stack) IsEmpty() bool {
	stack.key.RLock()
	defer stack.key.RUnlock()
	return stack.underlyer == nil || stack.underlyer.IsEmpty()
}
func ( stack * Stack ) IsEmpty ( ) bool { stack . key . RLock ( ) defer stack . key . RUnlock ( ) return stack . underlyer == nil || stack . underlyer . IsEmpty ( ) }
// IsEmpty tests the Stack to determine if it is populate or not.
IsEmpty tests the Stack to determine if it is populate or not .