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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_or_create(self, log_name, bucket_size):
 """ Gets or creates a log. :rtype: Timebucketedlog """

        try:
            return self[log_name]
        except RepositoryKeyError:
            return start_new_timebucketedlog(log_name, bucket_size=bucket_size)