---
features:
  - |
    Updated StreamingChunk to add the fields `tool_calls`, `tool_call_result`, `index`, and `start` to make it easier to format the stream in a streaming callback.
    - Added new dataclass ToolCallDelta for the `StreamingChunk.tool_calls` field to reflect that the arguments can be a string delta.
    - Updated `print_streaming_chunk` and `_convert_streaming_chunks_to_chat_message` utility methods to use these new fields. This especially improves the formatting when using `print_streaming_chunk` with Agent.
    - Updated `OpenAIGenerator`, `OpenAIChatGenerator`, `HuggingFaceAPIGenerator`, `HuggingFaceAPIChatGenerator`, `HuggingFaceLocalGenerator` and `HuggingFaceLocalChatGenerator` to follow the new dataclasses.
    - Updated `ToolInvoker` to follow the StreamingChunk dataclass.
