code: def _update_limits_from_api(self):
          
          self.connect()
          logger.info("Querying RDS DescribeAccountAttributes for limits")
          lims = self.conn.describe_account_attributes()['AccountQuotas']
          for lim in lims:
              if lim['AccountQuotaName'] not in self.API_NAME_TO_LIMIT:
                  logger.info('RDS DescribeAccountAttributes returned unknown'
                              'limit: %s (max: %s; used: %s)',
                              lim['AccountQuotaName'], lim['Max'], lim['Used'])
                  continue
              lname = self.API_NAME_TO_LIMIT[lim['AccountQuotaName']]
              self.limits[lname]._set_api_limit(lim['Max'])
              if len(self.limits[lname].get_current_usage()) < 1:
                  self.limits[lname]._add_current_usage(lim['Used'])
          logger.debug('Done setting limits from API.')
docs: Query RDS's DescribeAccountAttributes API action, and update limits
          with the quotas returned. Updates ``self.limits``.
  
          We ignore the usage information from the API,