'Load the last N deprioritized states will be extracted from the "deprioritized" stash and put to "active" stash.
N is controlled by \'num_fallback_states\'.
:param SimulationManager pg: The simulation manager.
:return: None'

def _load_fallback_states(self, pg):

    l.debug("No    more    active    states.    Load    some    deprioritized    states    to    'active'    stash.")
    if (('deprioritized' in pg.stashes) and pg.deprioritized):
        pg.active.extend(pg.deprioritized[(- self._num_fallback_states):])
        pg.stashes['deprioritized'] = pg.deprioritized[:(- self._num_fallback_states)]
