def _prev_idx(self):
        if self.repeat:
            return self.current_index
        if self.random:
            return self._random_idx()
        return self.current_index - 1
Performs the action described by a specified Action object.
dataset/ETHPy150Open beetbox/beets/beetsplug/bpd/__init__.py/BaseServer._prev_idx--crossover with--dataset/ETHPy150Open enthought/pyface/pyface/dock/dock_window.py/DockWindow.perform