// Peak get the top item of the stack.
Peak get the top item of the stack.
// Peak get the top item of the stack .
func (s *Stack) Peak() interface{} {
	e := s.list.Back()
	if e != nil {
		return e.Value
	}
	return nil
}
func ( s * Stack ) Peak ( ) interface { } { e := s . list . Back ( ) if e != nil { return e . Value } return nil }
Peak get the top item of the stack.
Peak get the top item of the stack .