private static boolean isMonitorExit(Exprent first) {
    if (first.type == Exprent.EXPRENT_MONITOR) {
      MonitorExprent expr = (MonitorExprent)first;
      return expr.getMonType() == MonitorExprent.MONITOR_EXIT &&
             expr.getValue().type == Exprent.EXPRENT_VAR &&
             !((VarExprent)expr.getValue()).isStack();
    }

    return false;
  }
private static boolean isMonitorExit(Exprent first)