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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 update_node(self, job_record):
 """ Updates job record property for a tree node associated with the given Job """

        if job_record.process_name not in self.process_hierarchy:
            raise ValueError('unable to update the node due to unknown process: {0}'.format(job_record.process_name))

        time_qualifier = self.process_hierarchy[job_record.process_name].process_entry.time_qualifier
        node = self._get_node(time_qualifier, job_record.timeperiod)
        node.job_record = job_record