def __init__(self, *, output_key: str, **kwargs: dict[str, Any]) -> None:
        """Constructor method.

        Args:
            output_key: chain output key.
            **kwargs: Keyword arguments to pass to the parent constructor.
        """
        super().__init__(**kwargs)

        self.output_key = output_key
Constructor method.

        Args:
            output_key: chain output key.
            **kwargs: Keyword arguments to pass to the parent constructor.
        
lanarky/adapters/langchain/callbacks.py