langchain/document_loaders/sitemap.py/SitemapLoader/load
class SitemapLoader:    def load(self) -> List[Document]:
        """Load sitemap."""
        if self.is_local:
            try:
                import bs4
            except ImportError:
                raise ImportError(
                    "beautifulsoup4 package not found, please install it"
                    " with `pip install beautifulsoup4`"
                )
            fp = open(self.web_path)
            soup = bs4.BeautifulSoup(fp, "xml")
        else:
            soup = self.scrape("xml")

        els = self.parse_sitemap(soup)

        if self.blocksize is not None:
            elblocks = list(_batch_block(els, self.blocksize))
            blockcount = len(elblocks)
            if blockcount - 1 < self.blocknum:
                raise ValueError(
                    "Selected sitemap does not contain enough blocks for given blocknum"
                )
            else:
                els = elblocks[self.blocknum]

        results = self.scrape_all([el["loc"].strip() for el in els if "loc" in el])

        return [
            Document(
                page_content=self.parsing_function(results[i]),
                metadata=self.meta_function(els[i], results[i]),
            )
            for i in range(len(results))
        ]