def sort(self):
        current = self.head
        while current.next != None:
            if current.next.expo > current.expo:
                tempexpo = current.getExpo()
                tempcoef = current.getCoef()
                current.coef = current.next.getCoef()
                current.expo = current.next.getExpo()
                current.next.coef = tempcoef
                current.next.expo = tempexpo
                self.sort()
            current = current.next
        return self