langchain/document_loaders/parsers/html/bs4.py/BS4HTMLParser/__init__
class BS4HTMLParser:    def __init__(
        self,
        *,
        features: str = "lxml",
        get_text_separator: str = "",
        **kwargs: Any,
    ) -> None:
        """Initialize a bs4 based HTML parser."""
        try:
            import bs4  # noqa:F401
        except ImportError:
            raise ValueError(
                "beautifulsoup4 package not found, please install it with "
                "`pip install beautifulsoup4`"
            )

        self.bs_kwargs = {"features": features, **kwargs}
        self.get_text_separator = get_text_separator