def sendall_stderr(self, s):
while s:<EOL><INDENT>sent = self.send_stderr(s)<EOL>s = s[sent:]<EOL><DEDENT>return None<EOL>
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