  
      def validation_failure_raises_response_exception(self, validator):
          """If form validation fails a ResourceException 400 (Bad Request) should be raised."""
          content = {}
          self.assertRaises(ErrorResponse, validator.validate_request, content, None)
  
      def validation_does_not_allow_extra_fields_by_default(self, validator):
          """If some (otherwise valid) content includes fields that are not in the form then validation should fail.
          It might be okay on normal form submission, but for Web APIs we oughta get strict, as it'll help show up
          broken clients more easily (eg submitting content with a misnamed field)"""
 
</s> remove         self.assertRaises(ErrorResponse, self.validator.validate_request, content, None)
 </s> add         self.assertRaises(ImmediateResponse, self.validator.validate_request, content, None) </s> remove         self.assertRaises(ErrorResponse, validator.validate_request, content, None)
 </s> add         self.assertRaises(ImmediateResponse, validator.validate_request, content, None) </s> remove         self.assertRaises(ErrorResponse, self.validator.validate_request, content, None)
 </s> add         self.assertRaises(ImmediateResponse, self.validator.validate_request, content, None) </s> remove         Raises a :exc:`response.ErrorResponse` with status code 400 (Bad Request) on failure.
 </s> add         Raises a :exc:`response.ImmediateResponse` with status code 400 (Bad Request) on failure. </s> remove         except ErrorResponse, response:
 </s> add         except ImmediateResponse, response:
        self.assertRaises(ImmediateResponse, validator.validate_request, content, None)
  
      def validation_failure_raises_response_exception(self, validator):
          """If form validation fails a ResourceException 400 (Bad Request) should be raised."""
          content = {}
        self.assertRaises(ImmediateResponse, validator.validate_request, content, None)
  
      def validation_does_not_allow_extra_fields_by_default(self, validator):
          """If some (otherwise valid) content includes fields that are not in the form then validation should fail.
          It might be okay on normal form submission, but for Web APIs we oughta get strict, as it'll help show up
          broken clients more easily (eg submitting content with a misnamed field)"""
keep keep keep keep replace keep keep keep keep keep
 cleaned a bit Response/ResponseMixin code, added some documentation + renamed ErrorResponse to ImmediateResponse 
djangorestframework/tests/validators.py