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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 convert_and_evaluate(self, system_id=1, split_sentences=False, rouge_args=None):
 """ Convert plain text summaries to ROUGE format and run ROUGE to evaluate the system summaries in system_dir against the model summaries in model_dir. Optionally split texts into sentences in case they aren't already. This is just a convenience method combining convert_summaries_to_rouge_format() and evaluate(). split_sentences: Optional argument specifying if sentences should be split. system_id: Optional system ID which will be printed in ROUGE's output. Returns: ROUGE output as string. """

        if split_sentences:
            self.split_sentences()
        self.__write_summaries()
        rouge_output = self.evaluate(system_id, rouge_args)
        return rouge_output