def rotate(self):
        self._index -= 1
        if self._index >= 0:
            return self._ring[self._index]
        return None
wrapper around IOChannel to only wait when a device become
dataset/ETHPy150Open ipython/ipython-py3k/IPython/frontend/qt/console/kill_ring.py/KillRing.rotate--crossover with--dataset/ETHPy150Open benoitc/flower/flower/io.py/wait_read