code: private void closeAndForgetOldResults() {
          Iterator<FieldSearchResultSQLImpl> iter =
                  m_currentResults.values().iterator();
          while (iter.hasNext()) {
              FieldSearchResultSQLImpl r = iter.next();
              if (r.isExpired()) {
                  logger.debug("listSession " + r.getToken()
                          + " expired; will forget it.");
                  iter.remove();
              }
          }
      }
docs: erase and cleanup expired stuff