def noop(self):
        """
        Perform no operation.

        This command is allowed in any state of connection.

        @rtype: L{Deferred}
        @return: A deferred whose callback will be invoked with a list
        of untagged status updates the server responds with.
        """
        d = self.sendCommand(Command(b'NOOP'))
        d.addCallback(self.__cbNoop)
        return d

        Perform no operation.

        This command is allowed in any state of connection.

        @rtype: L{Deferred}
        @return: A deferred whose callback will be invoked with a list
        of untagged status updates the server responds with.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/imap4.py