def handle_QUIT(self, line):
        """
        Require an I{OK} response to I{QUIT}.

        @param line: The I{QUIT} response.
        """
        if line[:3] != b'+OK':
            raise AssertionError(b'code is ' + line)

        Require an I{OK} response to I{QUIT}.

        @param line: The I{QUIT} response.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_pop3.py