  
          self.init_data = data
          self.init_files = files
          self.object = instance
          self.fields = self.get_fields()
  
          self._data = None
          self._files = None
          self._errors = None
  
 
</s> remove         self.assertRaises(AssertionError, PersonSerializerInvalidReadOnly, [])
 </s> add         serializer = PersonSerializerInvalidReadOnly()
        with self.assertRaises(AssertionError):
            serializer.fields </s> remove     def test_exception_for_incorect_fk(self):
 </s> add     def test_exception_for_incorrect_fk(self): </s> remove             TestSerializer(data={'name': 'foo'})
 </s> add             serializer.fields
  
          self.init_data = data
          self.init_files = files
          self.object = instance

  
          self._data = None
          self._files = None
          self._errors = None
  
keep keep keep keep replace keep keep keep keep keep
 Set up serializer fields lazily on-demand.

This avoids AppRegistryNotReady problems in Django 1.7 with nested serializers,
which are instantiated at import time, possibly before Django's app registry is
fully populated. 
rest_framework/serializers.py