def METHOD_NAME(self):
    self.mv.active_range = ((self.model_time +
                             timedelta(seconds=self.time_step / 2)),
                            InfDateTime('inf'))
    self.mv.prepare_for_model_step(self.sc, self.time_step,
                                   self.model_time)
    # model_time + time_step / 2 should be within active range
    assert self.mv.active is True