private boolean areResourcesPotentiallyRemaining() {
        if (fileResourceCrawler.isActive()) {
            return true;
        }
        return !fileResourceCrawler.isQueueEmpty();
    }
This is used instead of awaitTermination(), because that interrupts
the thread and then waits for its termination.  This politely waits.

@param causeForTermination reason for termination.
tika-batch/src/main/java/org/apache/tika/batch/BatchProcess.java