Multiple Issues with modify action for SAP SF OData API

I am using this library for developing a Python application that uses SAP SuccessFactors OData API. I spent last few days to resolve following issues with performing modify/update action but without any success. I finally came here to seek your help and suggestion. Please note that my application is already using this library for several OData query operations but I would prefer to use it also for update, create and delete operations too.

• Single update request using "PUT" method is making the desired update into HttpError because the status code returned is 200 instead of 204. This is because the update_entity() function in the class EntitySetProxy expects it to be 204 always.

• SAP SuccessFactors expects a custom method called "UPSERT" but the EntityModifyRequest class identifies it as invalid method.

• Batch update request even with only one update changeset is failing with the "BadRequestException" (400) error : "Missing boundary delimiter at line '4'.". Code wise all looks good and as suggested in the usage guide. Also, the header as well as the body (prints as below in [] parentheses) of the batch request looks fine too. Could it be because of 2 line breaks on line 4 of the body?

Batch Req. Header: [{'Content-Type': 'multipart/mixed;boundary=batch_1850_4989_2562'}]
Batch Req. Body: [
--batch_1850_4989_2562
Content-Type: multipart/mixed;boundary=changeset_2364_6806_2818

--changeset_2364_6806_2818
Content-Type: application/http
Content-Transfer-Encoding:binary

PUT PickListValueV2(PickListV2_effectiveStartDate=datetime'2020-10-23T00:00:00',PickListV2_id='employeeGroup',externalCode='EX') HTTP/1.1
Accept: application/json
Content-Type: application/json

{"label_en_DEBUG": "External Employee", "status": "A"}
--changeset_2364_6806_2818--
--batch_1850_4989_2562--]
Sample Code:

Bắt đầu với EntitySetProxy.update_entity() và EntityModifyRequest, sau đó tái hiện các ví dụ cập nhật PUT, UPSERT và theo lô từ issue và hướng dẫn sử dụng. Kiểm tra body của batch được tạo và việc xử lý response; được xem là hoàn tất khi 200 bản cập nhật được chấp nhận, UPSERT được nhận diện và request batch với một change set duy nhất được chấp nhận mà không có lỗi boundary.