def step_begin(self, step):
    super(StopAtStep, self).step_begin(step)
    if (self._last_step is None):
        self._last_step = ((step + self._num_steps) - 1)
    return []
def step_begin(self, step):
    super(StopAtStep, self).step_begin(step)
    if (self._last_step is None):
        self._last_step = ((step + self._num_steps) - 1)
    return []