async def _fetch_attachment_content(
        self, client: httpx.AsyncClient, message_id: str, attachment_id: str
    ) -> Optional[str]:
        """Fetch attachment content from Microsoft Graph API."""
        logger.debug(f"Fetching content for attachment {attachment_id}")
        attachment_url = (
            f"{self.GRAPH_BASE_URL}/me/messages/{message_id}/attachments/{attachment_id}"
        )
        attachment_data = await self._get_with_auth(client, attachment_url)
        return attachment_data.get("contentBytes")
Fetch attachment content from Microsoft Graph API.
backend/airweave/platform/sources/outlook_mail.py