How to use the eventy.managers.UpcomingManager function in eventy

def get_query_set(self):
        return super(UpcomingManager, self).get_query_set().filter(start__gte=datetime.now())

class EventTime(models.Model):
    """EventTime model
    
    This model does most of the heavy lifting as to whether """
    event = models.ForeignKey(Event, related_name='event_times')
    start = models.DateTimeField()
    end = models.DateTimeField(blank=True, null=True)
    place = models.ForeignKey(Place, blank=True, null=True)
    place_string = models.CharField(_('One-off place'), max_length=200, blank=True)
    is_all_day = models.BooleanField(default=False)
    notes = models.TextField(_('Notes'), blank=True, null=True)
    slug = models.SlugField(_('Event slug'), blank=True, editable=False)

    objects = models.Manager()
    upcoming_objects = UpcomingManager()

    class Meta:
        verbose_name = _('event time')
        verbose_name_plural = _('event times')
        get_latest_by = 'start'

    def __init__(self, *args, **kwargs):
        super (EventTime, self).__init__(*args, **kwargs)
        self._next = None
        self._previous = None

    @property
    def is_past(self):
        NOW = datetime.now().date
        if self.start < NOW:
            return True