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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 check(self, instance):
 """ Parse until the end of each tailer associated with this instance. We match instance and tailers based on the path to the Nagios configuration file Special case: Compatibility with the old conf when no conf file is specified but the path to the event_log is given """

        instance_key = instance.get('nagios_conf', instance.get('nagios_perf_cfg', instance.get('nagios_log', None)))

        # Bad configuration: This instance does not contain any necessary configuration
        if not instance_key or instance_key not in self.nagios_tails:
            raise Exception('No Nagios configuration file specified')
        for tailer in self.nagios_tails[instance_key]:
            tailer.check()