def ftp_FEAT(self):
        """
        Advertise the features supported by the server.

        http://tools.ietf.org/html/rfc2389
        """
        self.sendLine(RESPONSE[FEAT_OK][0])
        for feature in self.FEATURES:
            self.sendLine(' ' + feature)
        self.sendLine(RESPONSE[FEAT_OK][1])

        Advertise the features supported by the server.

        http://tools.ietf.org/html/rfc2389
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/ftp.py