models.py

class UrlModel(ManagementMixin):
  
    # bla bla bla
    
    @classmethod
    def get_clean_uris(cls):
        from .revisions import Revision
        from .files import File

        fstate = Revision.objects.filter(uri=models.OuterRef('pk')).order_by('-number')
        return cls.objects.filter(
        ).annotate(fstate=models.Subquery(
            fstate.values('file__state')[:1]
        )).filter(
            id__in=Revision.objects.filter(
                file__isnull=False
            ).order_by('uri', '-number')
             .distinct('uri', 'number')
             .values('uri__id'),
            is_active=True,
            state=cls.CHECKING,
        ).filter(
            models.Q(fstate=File.NOT_APPLICATION) |
            models.Q(fstate=File.CLEANED)
        )