public String pattern2() {
        if (words.isEmpty()) {
            throw new IllegalStateException();
        }

        List<String> patterns = new ArrayList<>();

        for (String word : words) {
            patterns.add(wordPattern(word));
        }
        //System.out.println(patterns);
        //System.out.println(mostCommon(patterns));
        return mostCommon(patterns);
    }

public int record2(char guess) {
        if (guessesLeft() < 1 || words.isEmpty()) {
            throw new IllegalStateException();
        } else if (guesses.contains(guess)) {
            throw new IllegalArgumentException();
        }

        int count = 0;
        guesses.add(guess);
        String pattern = pattern();
        Iterator<String> itr = words.iterator();

        while (itr.hasNext()) {
            if (!wordPattern(itr.next()).equals(pattern)) {
                itr.remove();
            }
        }

        for (int i = 0; i < pattern.length(); i++) {
            if (pattern.charAt(i) == guess) {
                count ++;
            }
        }
        if (count == 0) {
            guessesLeft -= 1;
        }
        return count;
    }

private String mostCommon2(List<String> patterns) {
        int max = 0;
        Map<String, Integer> map = new TreeMap<>();

        for (String pattern : patterns) {
            if (!map.containsKey(pattern)) {
                map.put(pattern, 1);
            } else {
                map.put(pattern, map.get(pattern) + 1);
            }
            if (map.get(pattern) > max) {
                max = map.get(pattern);
            }
        }
        for (String pattern : map.keySet()) {
            if (map.get(pattern) == max) {
                return pattern;
            }
        }
        return null; // don't necessarily want to have to do this ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    }