If sub-classed, run any shutdown operations on this method.

def shutdown(self, exitcode=0, exitmsg=None):
        '''
        If sub-classed, run any shutdown operations on this method.
        '''
        self.shutdown_log_info()
        msg = 'The salt master is shutdown. '
        if exitmsg is not None:
            exitmsg = msg + exitmsg
        else:
            exitmsg = msg.strip()
        super(Master, self).shutdown(exitcode, exitmsg)