def _load_doc(self, document_id) -> str:
        """
        Load a document from Feishu Docs.

        Args:
            document_id: the document id.

        Returns:
            The document text.

        """
        url = self.host + self.documents_raw_content_url_path.format(document_id)
        if self.tenant_access_token == "" or self.expire < time.time():
            self._update_tenant_access_token()
        headers = {
            "Authorization": f"Bearer {self.tenant_access_token}",
            "Content-Type": "application/json; charset=utf-8",
        }
        response = requests.get(url, headers=headers)
        return response.json()["data"]["content"]

        Load a document from Feishu Docs.

        Args:
            document_id: the document id.

        Returns:
            The document text.

        
llama-index-integrations/readers/llama-index-readers-feishu-docs/llama_index/readers/feishu_docs/base.py