- Enhanced the readability of the test case by reformatting the expected output and input message structures.
- This change maintains the same functionality while making the test code cleaner and easier to understand.
- The _Converter.items_to_messages method was incorrectly rejecting 'assistant'
as a valid role in conversation messages, causing runtime errors when processing
standard chat completion message formats.
- This fix enables proper handling of
complete conversation contexts that include both user and assistant messages.
