The contents of the message.
Reserved for additional payload data associated with the message.
Examples: response headers, logprobs, token counts, model name.
An optional name for the message.
An optional unique identifier for the message.
Get the text content of the message as a string.
Initialize server tool calls.
Parse server_tool_call_chunks from
ServerToolCallChunk objects.
Message chunk from an AI (yielded when streaming).
