      def validation_failed_due_to_invalid_field_returns_appropriate_message(self, validator):
          """If validation fails due to an invalid field, ensure the response contains a single field error"""
          content = {'qwerty': 'uiop', 'extra': 'extra'}
          try:
              validator.validate(content)
          except ErrorResponse, exc:           
              self.assertEqual(exc.response.raw_content, {'field-errors': {'extra': ['This field does not exist.']}})
          else:
              self.fail('ResourceException was not raised')  #pragma: no cover
      
 
</s> remove             FormValidator(view).validate(content)
 </s> add             MockResource(view).validate_request(content, None) </s> remove         content = {'qwerty': 'example', 'uiop':'example', 'readonly': 'read only', 'extra': 'extra'} 
        self.assertRaises(ErrorResponse, self.validator.validate, content)
 </s> add         content = {'qwerty': 'example', 'uiop':'example', 'readonly': 'read only', 'extra': 'extra'}
        self.assertRaises(ErrorResponse, self.validator.validate_request, content, None) </s> remove         self.assertEqual(self.validator.validate(content), content)
 </s> add         self.assertEqual(self.validator.validate_request(content, None), content) </s> remove         Wrapped by validate to hide the extra_fields option that the ModelValidatorMixin uses.
        extra_fields is a list of fields which are not defined by the form, but which we still
 </s> add         Wrapped by validate to hide the extra flags that are used in the implementation.

        allowed_extra_fields is a list of fields which are not defined by the form, but which we still
            validator.validate_request(content, None)
      def validation_failed_due_to_invalid_field_returns_appropriate_message(self, validator):
          """If validation fails due to an invalid field, ensure the response contains a single field error"""
          content = {'qwerty': 'uiop', 'extra': 'extra'}
          try:
            validator.validate_request(content, None)
          except ErrorResponse, exc:           
              self.assertEqual(exc.response.raw_content, {'field-errors': {'extra': ['This field does not exist.']}})
          else:
              self.fail('ResourceException was not raised')  #pragma: no cover
      
keep keep keep keep replace keep keep keep keep keep
 validators tests -> resources tests 
djangorestframework/tests/validators.py