Get the exit status of the program execution.

        Returns:
            int: Exit status as reported by the operating system,
                 or None if it is not available.

def get_exitstatus(self):
        """Get the exit status of the program execution.

        Returns:
            int: Exit status as reported by the operating system,
                 or None if it is not available.
        """
        logger.debug("Exit status is {0}".format(self._spawn.exitstatus))
        return self._spawn.exitstatus