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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 output_best_scores(self, best_epoch_str: str) -> None: """Output best scores to the filesystem"""

        BEST_SCORES_FILENAME = "best_scores.txt"
        with open(os.path.join(self.exp_dir, BEST_SCORES_FILENAME),
                  "w", encoding=ENCODING) as best_f:
            print(best_epoch_str, file=best_f, flush=True)