ChatCompletionChunk

{
    "id": "string",
    "object": "chat.completion.chunk",
    "created": 0,
    "model": "string",
    "choices": [
        {
            "index": 0,
            "delta": {
                "role": "string",
                "content": "string",
                "tool_calls": [
                    {}
                ]
            },
            "finish_reason": "string"
        }
    ],
    "usage": null
}