func (s *Stack) Resize(size int) {
	newl := make([]interface{}, len(*s), size)
	copy(newl, *s)
	*s = newl
}
func (s *Stack) Resize(size int) {
	newl := make([]interface{}, len(*s), size)
	copy(newl, *s)
	*s = newl
}
// Resize changes the size of the underlying buffer