code: def last_available_business_date(self, asset_manager_id, asset_ids, page_no=None, page_size=None):
          
          self.logger.info('Retrieving last available business dates for assets')
          url = '%s/last-available-business-date' % self.endpoint
          params = {'asset_manager_ids': [asset_manager_id],
                    'asset_ids': ','.join(asset_ids)}
          if page_no:
              params['page_no'] = page_no
          if page_size:
              params['page_size'] = page_size
          response = self.session.get(url, params=params)
          if response.ok:
              self.logger.info("Received %s assets' last available business date", len(response.json()))
              return response.json()
          else:
              self.logger.error(response.text)
              response.raise_for_status()
docs: Returns the last available business date for the assets so we know the 
          starting date for new data which needs to be downloaded from data providers.
          
          This method can only be invoked by system user