  from django.test import TestCase
  from rest_framework import serializers
  from rest_framework.tests.models import (Album, ActionItem, Anchor, BasicModel,
      BlankFieldModel, BlogPost, Book, CallableDefaultValueModel, DefaultValueModel,
      ManyToManyModel, Person, ReadOnlyManyToManyModel)
  
  
  class SubComment(object):
      def __init__(self, sub_comment):
          self.sub_comment = sub_comment
 
</s> remove     def __init__(self, instance=None, data=None, files=None, context=None, partial=False, **kwargs):
 </s> add     def __init__(self, instance=None, data=None, files=None,
                 context=None, partial=False, **kwargs): </s> remove             # Set up the field
            field.initialize(parent=self, field_name=key)
 </s> add 
    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo)
  from django.test import TestCase
  from rest_framework import serializers
  from rest_framework.tests.models import (Album, ActionItem, Anchor, BasicModel,
      BlankFieldModel, BlogPost, Book, CallableDefaultValueModel, DefaultValueModel,
    ManyToManyModel, Person, ReadOnlyManyToManyModel, Photo)
  
  
  class SubComment(object):
      def __init__(self, sub_comment):
          self.sub_comment = sub_comment
keep keep keep keep replace keep keep keep keep keep
 Clean up field initialization.  Fixes #497 
rest_framework/tests/serializer.py