  
          f.queryset = Category.objects.all()
          f.label_from_instance = lambda obj: "multicategory " + str(obj)
          self.assertEqual(list(f.choices), [
              (c1.pk, 'multicategory Entertainment'),
              (c2.pk, "multicategory It's a test"),
              (c3.pk, 'multicategory Third'),
              (c4.pk, 'multicategory Fourth')])
  
          # OneToOneField ###############################################################
  
          self.assertEqual(list(ImprovedArticleForm.base_fields), ['article'])
  
 
</s> remove         # OneToOneField ###############################################################
 </s> add     # OneToOneField ###############################################################
    def test_modelform_onetoonefield(self):
        class ImprovedArticleForm(forms.ModelForm):
            class Meta:
                model = ImprovedArticle
                fields = '__all__' </s> remove             f.clean([str(c3.id), str(c4.id)])
 </s> add             f.clean([str(self.c2.id), str(self.c3.id)]) </s> remove             (c1.pk, 'category Entertainment'),
            (c2.pk, "category It's a test"),
            (c3.pk, 'category Third'),
            (c4.pk, 'category Fourth')])

        # ModelMultipleChoiceField ####################################################
 </s> add             (self.c1.pk, 'category Entertainment'),
            (self.c2.pk, "category It's a test"),
            (self.c3.pk, 'category Third')]) </s> remove             f.clean([c4.id])
 </s> add             f.clean([self.c3.id]) </s> remove         self.assertEqual(list(ImprovedArticleForm.base_fields), ['article'])
 </s> add         class ImprovedArticleWithParentLinkForm(forms.ModelForm):
            class Meta:
                model = ImprovedArticleWithParentLink
                fields = '__all__'
            (self.c1.pk, 'multicategory Entertainment'),
            (self.c2.pk, "multicategory It's a test"),
            (self.c3.pk, 'multicategory Third')])
  
          f.queryset = Category.objects.all()
          f.label_from_instance = lambda obj: "multicategory " + str(obj)
          self.assertEqual(list(f.choices), [
            (self.c1.pk, 'multicategory Entertainment'),
            (self.c2.pk, "multicategory It's a test"),
            (self.c3.pk, 'multicategory Third')])
            (self.c1.pk, 'multicategory Entertainment'),
            (self.c2.pk, "multicategory It's a test"),
            (self.c3.pk, 'multicategory Third')])
            (self.c1.pk, 'multicategory Entertainment'),
            (self.c2.pk, "multicategory It's a test"),
            (self.c3.pk, 'multicategory Third')])
            (self.c1.pk, 'multicategory Entertainment'),
            (self.c2.pk, "multicategory It's a test"),
            (self.c3.pk, 'multicategory Third')])
  
          # OneToOneField ###############################################################
  
          self.assertEqual(list(ImprovedArticleForm.base_fields), ['article'])
  
keep keep keep keep replace replace replace replace keep keep keep keep keep
 Fixed #6103 -- Splitted tests in model_forms tests 
tests/model_forms/tests.py