@Override
        protected boolean lessThan(TokenDFTF arg0, TokenDFTF arg1) {
            if (arg0.df < arg1.df) {
                return true;
            } else if (arg0.df > arg1.df) {
                return false;
            }
            return arg1.token.compareTo(arg0.token) < 0;
        }
Utility class that reads in a UTF-8 input file with one document per row
and outputs the 20000 tokens with the highest document frequencies.
<p>
The CommmonTokensAnalyzer intentionally drops tokens shorter than 4 characters,
but includes bigrams for cjk.
<p>
It also has a include list for __email__ and __url__ and a skip list
for common html markup terms.
tika-eval/tika-eval-app/src/main/java/org/apache/tika/eval/app/tools/TopCommonTokenCounter.java