code: private static boolean statisticsObjectCheck(final ExecutorInfo statisticsObj1,
        final ExecutorInfo statisticsObj2, final String caller) {
      // both doesn't expose the info
      if (null == statisticsObj1 && null == statisticsObj2) {
        logger.debug(String.format("%s : neither of the executors exposed statistics info.",
            caller));
        return true;
      }
  
      //right side doesn't expose the info.
      if (null == statisticsObj2) {
        logger.debug(String.format(
            "%s : choosing left side and the right side executor doesn't expose statistics info",
            caller));
        return true;
      }
  
      //left side doesn't expose the info.
      if (null == statisticsObj1) {
        logger.debug(String.format(
            "%s : choosing right side and the left side executor doesn't expose statistics info",
            caller));
        return true;
      }
  
      // both not null
      return false;
    }
docs: <pre>
  helper function that does the object  on two statistics, comparator can leverage this function
  to provide
  shortcuts if   the statistics object is missing from one or both sides of the executors.
  </pre>
  
  @param stat1 the first statistics  object to be checked .
  @param stat2 the second statistics object to be checked.
  @param caller the name of the calling function, for logging purpose.
  @return true if the passed statistics are NOT both valid, a shortcut can be made (caller can
  consume the result), false otherwise.