'Return the `QuerySet` that will be used to look up the object.
This method is called by the default implementation of get_object() and
may not be called if get_object() is overridden.'

def get_queryset(self):

    if (self.queryset is None):
        if self.model:
            return self.model._default_manager.all()
        else:
            raise ImproperlyConfigured(('%(cls)s    is    missing    a    QuerySet.    Define    %(cls)s.model,    %(cls)s.queryset,    or    override    %(cls)s.get_queryset().' % {'cls': self.__class__.__name__}))
    return self.queryset.all()
