def bin_path(self):
        """
        The full path of the ROUGE binary (although it's technically
        a script), i.e. rouge_home_dir/ROUGE-1.5.5.pl

        """
        if self._bin_path is None:
            raise Exception(
                "ROUGE path not set. Please set the ROUGE home directory "
                "and ensure that ROUGE-1.5.5.pl exists in it.")
        return self._bin_path

        The full path of the ROUGE binary (although it's technically
        a script), i.e. rouge_home_dir/ROUGE-1.5.5.pl

        
s2s-ft/evaluations/bs_pyrouge.py