docs: def get_version(self, state=None, date=None):
          """
          Get a particular version of an item
  
          :param state: The state you want to get.
          :param date: Get a version that was published before or on this date.
          """
  
          version_model = self._meta._version_model
          q = version_model.objects.filter(object_id=self.pk)
          if state:
              q = version_model.normal.filter(object_id=self.pk, state=state)
  
          if date:
              q = q.filter(date_published__lte=date)
  
          q = q.order_by('-date_published')
  
          results = q[:1]
          if results:
              return results[0]
          return None