def METHOD_NAME(self):
    class MockField(UniqueFieldMixin):
        def __init__(self, **kwargs):
            for key, value in kwargs.items():
                setattr(self, key, value)
    self.uniq_field = MockField(
        attname='uniq_field',
        max_length=255,
        boolean_attr=True,
        non_boolean_attr='non_boolean_attr'
    )
    f_dummy = DummyRelationModel.objects.create()
    s_dummy = SecondDummyRelationModel.objects.create()
    t_dummy = ThirdDummyRelationModel.objects.create()
    post = PostWithUniqField.objects.create(
        uniq_field='test_uniq',
        common_field='first',
        another_common_field='second',
        many_to_one_field=f_dummy,
        one_to_one_field=s_dummy,
    )
    post.many_to_many_field.add(t_dummy)
    post.save()
    ReverseModel.objects.create(post_field=post)
    self.post = post