def cap_IMPLEMENTATION():
        """
        Return a string describing the POP3 server implementation.

        @rtype: L{bytes}
        @return: Server implementation information.
        """

        Return a string describing the POP3 server implementation.

        @rtype: L{bytes}
        @return: Server implementation information.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/interfaces.py