private void startWalkers(int numWalkers, Configuration conf, Context context) {
        LOG.info("Starting " + numWalkers + " concurrent walkers");
        for (int i = 0; i < numWalkers; i++) {
          Thread walker = new Thread(new ContinuousConcurrentWalker(conf, context));
          walker.start();
          walkers.add(walker);
        }
      }
Some ASCII art time:
<p>
[ . . . ] represents one batch of random longs of length WIDTH

<pre>
               _________________________
              |                  ______ |
              |                 |      ||
            .-+-----------------+-----.||
            | |                 |     |||
first   = [ . . . . . . . . . . . ]   |||
            ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^     |||
            | | | | | | | | | | |     |||
prev    = [ . . . . . . . . . . . ]   |||
            ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^     |||
            | | | | | | | | | | |     |||
current = [ . . . . . . . . . . . ]   |||
                                      |||
...                                   |||
                                      |||
last    = [ . . . . . . . . . . . ]   |||
            ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^_____|||
            |                 |________||
            |___________________________|
</pre>
hbase-it/src/test/java/org/apache/hadoop/hbase/test/IntegrationTestBigLinkedList.java