def METHOD_NAME(self, config, data_filename):
    """Filters a data file with jq and uploads the results to GCS."""
    filtered = 'daily-%s.json' % time.strftime('%Y-%m-%d')
    latest = '%s-latest.json' % config['metric']
    do_jq(config['jqfilter'], data_filename, filtered)
    self.copy(filtered, os.path.join(config['metric'], filtered))
    self.copy(filtered, latest)