langchain/document_loaders/onedrive.py/OneDriveLoader/_load_from_folder
class OneDriveLoader:    def _load_from_folder(self, folder: Type[Folder]) -> List[Document]:
        """
        Loads all supported document files from the specified folder
        and returns a list of Document objects.

        Args:
            folder (Type[Folder]): The folder object to load the documents from.

        Returns:
            List[Document]: A list of Document objects representing
            the loaded documents.

        """
        docs = []
        file_types = _SupportedFileTypes(file_types=["doc", "docx", "pdf"])
        file_mime_types = file_types.fetch_mime_types()
        items = folder.get_items()
        with tempfile.TemporaryDirectory() as temp_dir:
            file_path = f"{temp_dir}"
            os.makedirs(os.path.dirname(file_path), exist_ok=True)
            for file in items:
                if file.is_file:
                    if file.mime_type in list(file_mime_types.values()):
                        loader = OneDriveFileLoader(file=file)
                        docs.extend(loader.load())
        return docs