sheets = spreadsheet.get("sheets", [])
        documents = []
        for sheet in sheets:
            sheet_name = sheet["properties"]["title"]
            result = (
                sheets_service.spreadsheets()
                .values()
                .get(spreadsheetId=id, range=sheet_name)
                .execute()
            )
            values = result.get("values", [])
            if not values:
                continue  # empty sheet
            header = values[0]
            for i, row in enumerate(values[1:], start=1):
                metadata = {
                    "source": (
                        f"https://docs.google.com/spreadsheets/d/{id}/"
                        f"edit?gid={sheet['properties']['sheetId']}"
                    ),
                    "title": f"{spreadsheet['properties']['title']} - {sheet_name}",
                    "row": i,
                }
                content = []
                for j, v in enumerate(row):
                    title = header[j].strip() if len(header) > j else ""
                    content.append(f"{title}: {v.strip()}")
                page_content = "\n".join(content)
                documents.append(Document(page_content=page_content, metadata=metadata))
        return documents
    def _load_document_from_id(self, id: str) -> Document:
        """Load a document from an ID."""
        from io import BytesIO
        from googleapiclient.discovery import build
        from googleapiclient.errors import HttpError
        from googleapiclient.http import MediaIoBaseDownload
        creds = self._load_credentials()
        service = build("drive", "v3", credentials=creds)
        file = (
            service.files()
            .get(fileId=id, supportsAllDrives=True, fields="modifiedTime,name")
            .execute()