def add_to_current_action(self, controller):
        item = self.current_item
        self._history[self._index] = item + (controller,)
Centre the text on the specified line (y) using the optional
dataset/ETHPy150Open kwikteam/phy/phy/cluster/manual/_history.py/GlobalHistory.add_to_current_action--crossover with--dataset/ETHPy150Open peterbrittain/asciimatics/asciimatics/screen.py/_AbstractCanvas.centre