public void validate() {
      for (byte b1 = 'a'; b1 <= 'z'; b1++) {
        for (byte b2 = 'a'; b2 <= 'z'; b2++) {
          for (byte b3 = 'a'; b3 <= 'z'; b3++) {
            int count = seenRows[i(b1)][i(b2)][i(b3)];
            int expectedCount = 0;
            if (
              Bytes.compareTo(new byte[] { b1, b2, b3 }, startRow) >= 0
                && Bytes.compareTo(new byte[] { b1, b2, b3 }, stopRow) < 0
            ) {
              expectedCount = 1;
            }
            if (count != expectedCount) {
              String row = new String(new byte[] { b1, b2, b3 }, StandardCharsets.UTF_8);
              throw new RuntimeException("Row:" + row + " has a seen count of " + count + " "
                + "instead of " + expectedCount);
            }
          }
        }
      }
    }
Validate that all the rows between startRow and stopRow are seen exactly once, and all other
rows none
hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtil.java