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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_file(cls, filename=None):
 """ Load settings from an rtv configuration file. """


        if filename is None:
            filename = CONFIG

        config = configparser.ConfigParser()
        if os.path.exists(filename):
            with codecs.open(filename, encoding='utf-8') as fp:
                config.readfp(fp)

        return cls._parse_rtv_file(config)