<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def sendall_stderr(self, s):
 """ Send data to the channel's "stderr" stream, without allowing partial results. Unlike `send_stderr`, this method continues to send data from the given string until all data has been sent or an error occurs. Nothing is returned. :param str s: data to send to the client as "stderr" output. :raises socket.timeout: if sending stalled for longer than the timeout set by `settimeout`. :raises socket.error: if an error occurred before the entire string was sent. .. versionadded:: 1.1 """

        while s:
            sent = self.send_stderr(s)
            s = s[sent:]
        return None