code: def get_report_overview(self, month, file_path):
          
          api = self._get_api(billing.DefaultApi)
          month = self._month_converter(month)
          response = api.get_billing_report(month=month)
          if file_path and response:
              content = api.api_client.sanitize_for_serialization(response.to_dict())
              with open(file_path, 'w') as fh:
                  fh.write(
                      json.dumps(
                          content,
                          sort_keys=True,
                          indent=2,
                      )
                  )
          return response
docs: Downloads a report overview
  
          :param month: month as datetime instance, or string in YYYY-MM format
          :type month: str or datetime
          :param str file_path: location to store output file
          :return: outcome
          :rtype: True or None