langchain/document_loaders/trello.py/TrelloLoader/from_credentials
class TrelloLoader:    def from_credentials(
        cls,
        board_name: str,
        *,
        api_key: Optional[str] = None,
        token: Optional[str] = None,
        **kwargs: Any,
    ) -> TrelloLoader:
        """Convenience constructor that builds TrelloClient init param for you.

        Args:
            board_name: The name of the Trello board.
            api_key: Trello API key. Can also be specified as environment variable
                TRELLO_API_KEY.
            token: Trello token. Can also be specified as environment variable
                TRELLO_TOKEN.
            include_card_name: Whether to include the name of the card in the document.
            include_comments: Whether to include the comments on the card in the
                document.
            include_checklist: Whether to include the checklist on the card in the
                document.
            card_filter: Filter on card status. Valid values are "closed", "open",
                "all".
            extra_metadata: List of additional metadata fields to include as document
                metadata.Valid values are "due_date", "labels", "list", "closed".
        """

        try:
            from trello import TrelloClient  # type: ignore
        except ImportError as ex:
            raise ImportError(
                "Could not import trello python package. "
                "Please install it with `pip install py-trello`."
            ) from ex
        api_key = api_key or get_from_env("api_key", "TRELLO_API_KEY")
        token = token or get_from_env("token", "TRELLO_TOKEN")
        client = TrelloClient(api_key=api_key, token=token)
        return cls(client, board_name, **kwargs)