/// Swap the topmost plank
    pub fn swap_latest(&mut self, ms: &mut MaterialStorage) {
        let number_of_planks = self.planks.len();
        if number_of_planks >= 2 {
            self.pop(ms);
            self.pop(ms);
            if let Some(plank) = ms.get_used() {
                self.add(plank);
            }
            if let Some(plank) = ms.get_used() {
                self.add(plank);
            }
        }
    }