def METHOD_NAME(db, admin_info, history_mock):
    FakeModel = get_fake_model(model_base=models.UUIDModel)
    class CustomValidation(validations.BaseValidation):
        def validate(self, mutation, data, info):
            info.context.user.group = "foobar"
            return data
    class MySerializer(serializers.ModelSerializer):
        validation_classes = [CustomValidation]
        class Meta:
            model = FakeModel
            fields = "__all__"
    class CustomNode(types.DjangoObjectType):
        class Meta:
            model = FakeModel
            fields = "__all__"
    class MyMutation(mutation.Mutation):
        class Meta:
            serializer_class = MySerializer
    MyMutation.mutate_and_get_payload(None, admin_info)
    assert FakeModel.objects.first().created_by_group == "foobar"