code: def skip(self):
          
          if self.skip_me is not None:
              return self.skip_me
  
          cls = self.instance.__class__
          using = router.db_for_write(cls, instance=self.instance)
          collector = Collector(using=using)
          collector.collect([self.instance], collect_related=False)
          sub_objects = sum([list(i) for i in collector.data.values()], [])
          sub_objects_parents = [so._meta.parents for so in sub_objects]
          if [self.model in p for p in sub_objects_parents].count(True) == 1:
              # since this instance isn't explicitly created, it's variable name
              # can't be referenced in the script, so record None in context dict
              pk_name = self.instance._meta.pk.name
              key = '%s_%s' % (self.model.__name__, getattr(self.instance, pk_name))
              self.context[key] = None
              self.skip_me = True
          else:
              self.skip_me = False
  
          return self.skip_me
docs: Determine whether or not this object should be skipped.
          If this model instance is a parent of a single subclassed
          instance, skip it. The subclassed instance will create this
          parent instance for us.
  
          TODO: Allow the user to force its creation?