private long selectLoop() throws InterruptedException {
          synchronized (flushedLoopsLock) {
            while (flushedLoops.isEmpty() && !walkersStop) {
              flushedLoopsLock.wait();
            }
            if (walkersStop) {
              throw new InterruptedException();
            }
            return flushedLoops.get(ThreadLocalRandom.current().nextInt(flushedLoops.size()));
          }
        }
Randomly selects and walks a random flushed loop concurrently with the Generator Mapper by
spawning ConcurrentWalker's with specified StartNodes. These ConcurrentWalker's are
configured to only log erroneous nodes.
hbase-it/src/test/java/org/apache/hadoop/hbase/test/IntegrationTestBigLinkedList.java