def message(self):
        """
        A string received over the network that explains the error to a human.
        """
        # Python 2.6 deprecates assigning to the 'message' attribute of an
        # exception. We define this read-only property here in order to
        # prevent the warning about deprecation while maintaining backwards
        # compatibility with object clients that rely on the 'message'
        # attribute being set correctly. See bug #3897.
        return self._message

        A string received over the network that explains the error to a human.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/ssh/filetransfer.py