Updates values as if we had iterated over the for

def iterate(self):
        """
        Updates values as if we had iterated over the for
        """
        self.counter += 1
        self.counter0 += 1
        self.revcounter -= 1
        self.revcounter0 -= 1
        self.first = False
        self.last = (self.revcounter0 == self.len_values - 1)