Send a raw BSON message or raise ConnectionFailure.

        If a network exception is raised, the socket is closed.

def send_message(self, message, max_doc_size):
        """Send a raw BSON message or raise ConnectionFailure.

        If a network exception is raised, the socket is closed.
        """
        if (self.max_bson_size is not None
                and max_doc_size > self.max_bson_size):
            raise DocumentTooLarge(
                "BSON document too large (%d bytes) - the connected server "
                "supports BSON document sizes up to %d bytes." %
                (max_doc_size, self.max_bson_size))

        try:
            self.sock.sendall(message)
        except BaseException as error:
            self._raise_connection_failure(error)