def from_string(cls, json_str: str, **kwargs: Any) -> "ChatSummaryMemoryBuffer":
        """Create a chat memory buffer from a string."""
        dict_obj = json.loads(json_str)
        return cls.from_dict(dict_obj, **kwargs)
Create a chat memory buffer from a string.
llama-index-core/llama_index/core/memory/chat_summary_memory_buffer.py