private void addTokenDiff(String token, int tokenCount, int diff, TokenCountDiffQueue queue) {
        if (queue.top() == null || queue.size() < topN || diff >= queue.top().diff) {
            queue.insertWithOverflow(new TokenCountDiff(token, diff, tokenCount));
        }

    }
Computes some corpus contrast statistics.
<p>
Not thread safe.
tika-eval/tika-eval-core/src/main/java/org/apache/tika/eval/core/tokens/TokenContraster.java