protected void runVerify(String outputDir, int numReducers, long expectedNumNodes)
      throws Exception {
      Path outputPath = new Path(outputDir);
      UUID uuid = UUID.randomUUID(); // create a random UUID.
      Path iterationOutput = new Path(outputPath, uuid.toString());

      Verify verify = new Verify();
      verify.setConf(getConf());
      int retCode = verify.run(iterationOutput, numReducers);
      if (retCode > 0) {
        throw new RuntimeException("Verify.run failed with return code: " + retCode);
      }

      if (!verify.verify(expectedNumNodes)) {
        throw new RuntimeException("Verify.verify failed");
      }
      LOG.info("Verify finished with success. Total nodes=" + expectedNumNodes);
    }
Executes Generate and Verify in a loop. Data is not cleaned between runs, so each iteration
adds more data.
hbase-it/src/test/java/org/apache/hadoop/hbase/test/IntegrationTestBigLinkedList.java