code: def _load_region(self, acct_id, region_name, path):
          
          lim_path = os.path.join(path, 'limit_overrides.json')
          thresh_path = os.path.join(path, 'threshold_overrides.json')
          res = {'limit_overrides': {}, 'threshold_overrides': {}}
          if os.path.exists(lim_path):
              with open(lim_path, 'r') as fh:
                  res['limit_overrides'] = json.loads(fh.read())
          if os.path.exists(thresh_path):
              with open(thresh_path, 'r') as fh:
                  res['threshold_overrides'] = json.loads(fh.read())
          self._config[acct_id]['regions'][region_name] = res
docs: load config from a single per-region subdirectory of an account