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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 parse(self, limit=None):
 """ IMPC data is delivered in three separate csv files OR in one integrated file, each with the same file format. :param limit: :return: """

        if limit is not None:
            LOG.info("Only parsing first %s rows fo each file", str(limit))

        LOG.info("Parsing files...")

        if self.test_only:
            self.test_mode = True

        # for f in ['impc', 'euro', 'mgd', '3i']:
        for f in ['all']:
            file = '/'.join((self.rawdir, self.files[f]['file']))
            self._process_data(file, limit)

        LOG.info("Finished parsing")

        return