def step(self):
        """Run the next child task and wait for completion (no timeout)."""
        if self.index >= len(self.tasklist):
            raise TaskError(self % "step(): sequential compound task %s finished")

        self.check_state()

        # Select next task from the set and advance the index
        self.task = self.tasklist[self.index]
        self.index += 1

        return self.runTask(self.task)
dataset/ETHPy150Open ejeschke/ginga/ginga/misc/Task.py/SequentialTaskset.step/swapped operands of `%`