Create_Attachment doesn't seem to work

The python create_attachment call in the git client doesn't seem to work correctly. If you use it as currently implemented you get a 'azure.devops.exceptions.AzureDevOpsServiceError: Nullable object must have a value' exception.

I saw the example as part of issue 129: #129 but that throws the same exception.

If I instead change the create_attachment call to:

def create_attachment(self, upload_stream, file_name, repository_id, pull_request_id, project=None, **kwargs):
        """CreateAttachment.
        [Preview API] Attach a new file to a pull request.
        :param object upload_stream: Stream to upload
        :param str file_name: The name of the file.
        :param str repository_id: The repository ID of the pull request’s target branch.
        :param int pull_request_id: ID of the pull request.
        :param str project: Project ID or project name
        :rtype: :class:`<Attachment> <azure.devops.v6_0.git.models.Attachment>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        if file_name is not None:
            route_values['fileName'] = self._serialize.url('file_name', file_name, 'str')
        if repository_id is not None:
            route_values['repositoryId'] = self._serialize.url('repository_id', repository_id, 'str')
        if pull_request_id is not None:
            route_values['pullRequestId'] = self._serialize.url('pull_request_id', pull_request_id, 'int')
        if "callback" in kwargs:
            callback = kwargs["callback"]
        else:
            callback = None
        # content = self._client.stream_upload(upload_stream, callback=callback)
        response = self._send(http_method='POST',
                              location_id='965d9361-878b-413b-a494-45d5b5fd8ab7',
                              version='6.0-preview.1',
                              route_values=route_values,
                              content=upload_stream.read(),
                              media_type='application/octet-stream')
        return self._deserialize('Attachment', response)

things work.

[SpinyCucumber]

I'm experiencing this as well in October of 2023.
Here's a small example, similar to the example in #129 mentioned above:

from azure.devops.connection import Connection
from azure.devops.v7_0.git.git_client import GitClient
from azure.devops.v7_0.git.models import *
from msrest.authentication import BasicAuthentication
from pathlib import Path

# Insert your own credentials/IDs here
personal_access_token = "notarealpersonalaccesstoken"
organization_url = "https://dev.azure.com/notarealorganization"
authentication = BasicAuthentication("", personal_access_token)
repository_id = "some-letters-and-numbers"
pull_request_id = 123456

connection = Connection(organization_url, authentication)
client: GitClient = connection.clients.get_git_client()

# Open file and call create attachment
# Expect file to be in same directory as script
file_name = "test.jpg"
upload_path = Path(__file__).parent / file_name
with upload_path.open("rb") as upload:
    result = client.create_attachment(upload, file_name, repository_id, pull_request_id)
    print(result)

When I run this code, I receive the following error:

Traceback (most recent call last):
  File ".\create_attachment.py", line 22, in <module>
    result = client.create_attachment(upload, file_name, repository_id, pull_request_id, project)
  File "C:\SomeDirectory\.venv\lib\site-packages\azure\devops\v7_0\git\git_client_base.py", line 1229, in create_attachment
    media_type='application/octet-stream')
  File "C:\SomeDirectory\.venv\lib\site-packages\azure\devops\client.py", line 104, in _send
    response = self._send_request(request=request, headers=headers, content=content, media_type=media_type)
  File "C:\SomeDirectory\.venv\lib\site-packages\azure\devops\client.py", line 68, in _send_request
    self._handle_error(request, response)
  File "C:\SomeDirectory\.venv\lib\site-packages\azure\devops\client.py", line 270, in _handle_error
    raise AzureDevOpsServiceError(wrapped_exception)
azure.devops.exceptions.AzureDevOpsServiceError: Nullable object must have a value.

Currently, I'm using Python 3.7.4 with azure-devops 7.1.0b3.

I can also vouch that using the create_attachment implementation given in the original post prevents the error, however it requires reading the entire file into memory, which is less than ideal.