How to use the kolibri.core.auth.models.Classroom.objects.filter function in kolibri

def _get_class_models(self, dataset_id):
        dataset_id_filter = Q(dataset_id=dataset_id)
        return GroupDeletion(
            "Class models",
            querysets=[
                ExamAssignment.objects.filter(dataset_id_filter),
                Exam.objects.filter(dataset_id_filter),
                LessonAssignment.objects.filter(dataset_id_filter),
                Lesson.objects.filter(dataset_id_filter),
                AdHocGroup.objects.filter(dataset_id_filter),
                LearnerGroup.objects.filter(dataset_id_filter),
                Classroom.objects.filter(dataset_id_filter),
            ],

def get_delete(self, options, keeping_users, update_classes):
        if not options["delete"]:
            return ([], [])
        users_not_to_delete = [u.id for u in keeping_users]
        admins = self.default_facility.get_admins()
        users_not_to_delete += admins.values_list("id", flat=True)
        if options["userid"]:
            users_not_to_delete.append(options["userid"])
        users_to_delete = FacilityUser.objects.filter(
            facility=self.default_facility
        ).exclude(id__in=users_not_to_delete)
        # Classes not included in the csv will be cleared of users,
        # but not deleted to keep possible lessons and quizzes created for them:
        classes_not_to_clear = [c.id for c in update_classes]
        classes_to_clear = (
            Classroom.objects.filter(parent=self.default_facility)
            .exclude(id__in=classes_not_to_clear)
            .values_list("id", flat=True)
        )

        return (users_to_delete, classes_to_clear)

# users_with_logs
        "uwl": users_with_logs,
        # anon_visitors_with_logs
        "vwl": anon_visitors_with_logs,
        # first
        "f" : first_interaction_timestamp("%Y-%m-%d") if first_interaction_timestamp else None,
        # last
        "l": last_interaction_timestamp("%Y-%m-%d") if last_interaction_timestamp else None,
        # summ_started
        "ss": summarylogs.count(),
        # summ_complete
        "sc": summarylogs.exclude(completion_timestamp=None).count(),
        # sess_kinds
        "sk": sesslogs_by_kind,
        # class_count
        "crc": Classroom.objects.filter(dataset_id=dataset_id).count(),
        # group_count
        "grc": LearnerGroup.objects.filter(dataset_id=dataset_id).count(),
        # lesson_count
        "lec": Lesson.objects.filter(dataset_id=dataset_id).count(),
        # exam_count
        "ec": Exam.objects.filter(dataset_id=dataset_id).count(),
        # exam_log_count
        "elc": ExamLog.objects.filter(dataset_id=dataset_id).count(),
        # att_log_count
        "alc": AttemptLog.objects.filter(dataset_id=dataset_id).count(),
        # exam_att_log_count
        "ealc": ExamAttemptLog.objects.filter(dataset_id=dataset_id).count(),
        # sess_user_count
        "suc": contsessions_user.count(),
        # sess_anon_count
        "sac": contsessions_anon.count(),

def annotate_queryset(self, queryset):
        return (
            queryset.annotate(
                num_users=SQCount(
                    FacilityUser.objects.filter(facility=OuterRef("id")), field="id"
                )
            )
            .annotate(
                num_classrooms=SQCount(
                    Classroom.objects.filter(parent=OuterRef("id")), field="id"
                )
            )
            .annotate(
                last_synced=Subquery(
                    TransferSession.objects.filter(
                        filter=Cast(OuterRef("dataset"), TextField())
                    )
                    .order_by("-last_activity_timestamp")
                    .values("last_activity_timestamp")
                )

logger.info("Creating csv file {filename}".format(filename=filepath))
        writer.writeheader()
        usernames = set()

        query = (
            queryset.values("pk")
            .annotate(
                kind=Subquery(
                    Role.objects.filter(collection_id=facility.id)
                    .values("kind")
                    .filter(user_id=OuterRef("id"))
                )
            )
            .annotate(
                enrolled=GroupConcatSubquery(
                    Classroom.objects.filter(membership__user_id=OuterRef("id")).values(
                        "name"
                    ),
                    field="name",
                )
            )
            .annotate(
                assigned=GroupConcatSubquery(
                    Classroom.objects.filter(
                        role__kind="coach", role__user=OuterRef("id")
                    ).values("name"),
                    field="name",
                )
            )
        )

        for item in query.values(*db_columns):

def get_num_classrooms(self, instance):
        return Classroom.objects.filter(parent=instance).count()