How to use the devilry.apps.core.models.RelatedExaminer function in devilry

def add_relatedexaminers(self, *users):
        relatedexaminers = []
        for user in users:
            if isinstance(user, RelatedExaminer):
                relatedexaminer = user
            else:
                relatedexaminer = RelatedExaminer(
                user=user)
            relatedexaminer.period = self.period
            relatedexaminers.append(relatedexaminer)
        RelatedExaminer.objects.bulk_create(relatedexaminers)
        return self

def add_relatedexaminers(self, *users):
        relatedexaminers = []
        for user in users:
            if isinstance(user, RelatedExaminer):
                relatedexaminer = user
            else:
                relatedexaminer = RelatedExaminer(
                user=user)
            relatedexaminer.period = self.period
            relatedexaminers.append(relatedexaminer)
        RelatedExaminer.objects.bulk_create(relatedexaminers)
        return self

def add_relatedexaminers(self, *users):
        relatedexaminers = []
        for user in users:
            if isinstance(user, RelatedExaminer):
                relatedexaminer = user
            else:
                relatedexaminer = RelatedExaminer(
                user=user)
            relatedexaminer.period = self.period
            relatedexaminers.append(relatedexaminer)
        RelatedExaminer.objects.bulk_create(relatedexaminers)
        return self

def add_relatedexaminers(self, *users):
        relatedexaminers = []
        for user in users:
            if isinstance(user, RelatedExaminer):
                relatedexaminer = user
            else:
                relatedexaminer = RelatedExaminer(
                    user=user)
            relatedexaminer.period = self.period
            relatedexaminers.append(relatedexaminer)
        RelatedExaminer.objects.bulk_create(relatedexaminers)
        return self

def get_relatedexaminer(self, relatedexaminer_id):
        try:
            return coremodels.RelatedExaminer.objects.get(id=relatedexaminer_id)
        except coremodels.RelatedExaminer.DoesNotExist:
            raise NotFound({'error': 'Examiner does not exist.'})

first_deadline=assignment_publishing_time + timezone.timedelta(days=7),
                points_to_grade_mapper=coremodels.Assignment.POINTS_TO_GRADE_MAPPER_RAW_POINTS,
                max_points=50,
                parentnode=period
            )
            assignment.save()

            relatedexaminers = []
            for num in range(10):
                examiner_user = get_user_model()(
                    fullname='Examiner#{}'.format(num),
                    shortname='examiner#{}@example.com'.format(num)
                )
                examiner_user.save()
                print(('Create examineruser#{}'.format(num)))
                relatedexaminer = coremodels.RelatedExaminer(
                    user=examiner_user,
                    period=period
                )
                relatedexaminer.save()
                relatedexaminers.append(relatedexaminer.id)

            grading_published_datetime = assignment_publishing_time + timezone.timedelta(days=8)
            assignment_groups = []

            # Create assignment groups and add students
            for num in range(num_students):
                assignment_group = coremodels.AssignmentGroup(
                    parentnode=assignment
                )
                assignment_group.save()
                print(('Create assignment group#{}'.format(num)))

def get_model_class(self):
        return RelatedExaminer

def __get_relatedexaminer_ids(self):
        return RelatedExaminer.objects\
            .select_related('user')\
            .filter(period_id=self.assignment.parentnode_id) \
            .filter(examiner__assignmentgroup__parentnode_id=self.assignment.id)\
            .only('id')\
            .distinct('id')\
            .values_list('id', flat=True)

def __get_relatedexaminer(self):
        try:
            return self.get_relatedexaminer_queryset().get(id=self.get_relatedexaminer_id())
        except RelatedExaminer.DoesNotExist:
            raise Http404()

# and a new assingment in the current period
        student = UserBuilder('psylocke', full_name='Elisabeth Braddock').user
        examiner = UserBuilder('magneto', full_name='Erik Lehnsherr').user
        examiner2 = UserBuilder('beast', full_name='Hank McCoy').user

        first_deadline = timezone.now() - timezone.timedelta(weeks=2, days=1)

        periodbuilder = self.duckburgh.add_subject(
            short_name='inf7020',
            long_name='INF7020 Programming for World Domination and Crashing Non-Mutant Economy',
        ).add_6month_active_period(
            short_name='testsemester',
            long_name='Testsemester',
            relatedexaminers=[
                RelatedExaminer(user=examiner),
                RelatedExaminer(user=examiner2),
            ],
            relatedstudents=[student])
        assignmentgroupbuilder = periodbuilder.add_assignment(
            'Oblig 1 - Domination',
            passing_grade_min_points=3,
            max_points=10,
            first_deadline=first_deadline
        ).add_group()

        assignmentgroupbuilder.add_candidates_from_relatedstudents(
            *periodbuilder.period.relatedstudent_set.all())
        assignmentgroupbuilder.add_examiners(examiner, examiner2)

        feedbacksetbuilder1 = assignmentgroupbuilder.add_feedback_set(
            points=1,
            published_by=examiner,