docs: def send_message(self, message, all_credentials):
          """Send an unacknowledged message to MongoDB.
  
          Can raise ConnectionFailure.
  
          :Parameters:
            - `message`: (request_id, data).
            - `all_credentials`: dict, maps auth source to MongoCredential.
          """
          _, data, max_doc_size = self._split_message(message)
          with self.get_socket(all_credentials) as sock_info:
              sock_info.send_message(data, max_doc_size)