private void recordFailure(final long keyToRead) {
      numReadFailures.addAndGet(1);
      LOG.debug("[" + readerId + "] FAILED read, key = " + (keyToRead + "") + ", "
        + "time from start: " + (EnvironmentEdgeManager.currentTime() - startTimeMs) + " ms");
    }
Maps user with Table instance. Because the table instance has to be created per user inorder to
work in that user's context
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/util/MultiThreadedReaderWithACL.java