  from django.utils.translation import ugettext_lazy as _
  from rest_framework import serializers, fields, relations
  from rest_framework.tests.models import (HasPositiveIntegerAsChoice, Album, ActionItem, Anchor, BasicModel,
      BlankFieldModel, BlogPost, BlogPostComment, Book, CallableDefaultValueModel, DefaultValueModel,
      ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo, RESTFrameworkModel)
  from rest_framework.tests.models import BasicModelSerializer
  import datetime
  import pickle
  
  
 
</s> remove 
class OneToOneTarget(models.Model):
    name = models.CharField(max_length=100)
 </s> add from .models import OneToOneTarget </s> remove         class DVOAFModel(RESTFrameworkModel):
            positive_integer_field = models.PositiveIntegerField(blank=True)
            positive_small_integer_field = models.PositiveSmallIntegerField(blank=True)
            email_field = models.EmailField(blank=True)
            file_field = models.FileField(blank=True)
            image_field = models.ImageField(blank=True)
            slug_field = models.SlugField(blank=True)
            url_field = models.URLField(blank=True)
 </s> add  </s> remove         class AMOAFModel(RESTFrameworkModel):
            char_field = models.CharField(max_length=1024, blank=True)
            comma_separated_integer_field = models.CommaSeparatedIntegerField(max_length=1024, blank=True)
            decimal_field = models.DecimalField(max_digits=64, decimal_places=32, blank=True)
            email_field = models.EmailField(max_length=1024, blank=True)
            file_field = models.FileField(max_length=1024, blank=True)
            image_field = models.ImageField(max_length=1024, blank=True)
            slug_field = models.SlugField(max_length=1024, blank=True)
            url_field = models.URLField(max_length=1024, blank=True)
 </s> add 
    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo, RESTFrameworkModel, AMOAFModel, DVOAFModel)
  from django.utils.translation import ugettext_lazy as _
  from rest_framework import serializers, fields, relations
  from rest_framework.tests.models import (HasPositiveIntegerAsChoice, Album, ActionItem, Anchor, BasicModel,
      BlankFieldModel, BlogPost, BlogPostComment, Book, CallableDefaultValueModel, DefaultValueModel,
    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo, RESTFrameworkModel, AMOAFModel, DVOAFModel)
  from rest_framework.tests.models import BasicModelSerializer
  import datetime
  import pickle
  
  
keep keep keep keep replace keep keep keep keep keep
 Moved all the reused models to the models files to avoid conflicts with the refactored apps. 
rest_framework/tests/test_serializer.py