def harvest(self, start_date=None, end_date=None):

        start_date = start_date or date.today() - timedelta(settings.DAYS_BACK)
        end_date = end_date or date.today()

        delta = end_date - start_date

        date_strings = []
        for i in range(delta.days + 1):
            date_strings.append(start_date + timedelta(days=i))

        search_urls = []
        for adate in date_strings:
            self.URL.args['q'] = 'date:{}'.format(adate)

            search_urls.append(self.URL.url)

        records = self.get_records(search_urls)
        records_list = []
        for record in records:
            format_type = record['publisher']
            if format_type.lower() == "biomed central":
                records_list.append(RawDocument({
                    'doc': json.dumps(record),
                    'source': self.short_name,
                    'docID': record['identifier'],
                    'filetype': 'json'
                }))
        return records_list
dataset/ETHPy150Open CenterForOpenScience/scrapi/scrapi/harvesters/biomedcentral.py/BiomedCentralHarvester.harvest/original