/guava/guava/src/com/google/common/util/concurrent/CycleDetectingLockFactory.java
aboutToAcquire( readWriteLock) ;lockStateChanged( readWriteLock) ;
lockStateChanged ( readWriteLock ) ;
@Override public void lockInterruptibly() throws InterruptedException { aboutToAcquire(readWriteLock); try { super.lockInterruptibly(); } finally { <extra_id_0> } } @Override public boolean tryLock() { aboutToAcquire(readWriteLock); try {