def err_write(self, msg, **kwargs):
if self._thread_invalid():<EOL><INDENT>self.async_call(self.err_write, msg, **kwargs)<EOL>return<EOL><DEDENT>return self.request('<STR_LIT>', msg, **kwargs)<EOL>
r"""Print `msg` as an error message.

        The message is buffered (won't display) until linefeed ("\n").