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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_icinga_stats(self, app_stats):
 """ Extract metrics from 'programstatus' """

        stats = {}
        stats = dict(stats.items() + self._get_active_stats(app_stats).items())
        stats = dict(stats.items() + self._get_cached_stats(app_stats).items())
        stats = dict(
            stats.items() + self._get_command_execution(app_stats).items())
        stats = dict(
            stats.items() + self._get_externalcmd_stats(app_stats).items())
        stats["uptime"] = self._get_uptime(app_stats)
        return stats