@Override
public int makeGuess(char letter) throws IllegalStateException, IllegalArgumentException {
   if (letter < 97 || letter > 122) {
       throw new IllegalArgumentException();
   }
   if (previousGuesses.contains(letter)) {
       throw new IllegalArgumentException();
   }
   previousGuesses.add(letter);
   if (guessesLeft < 1) {
       throw new IllegalStateException();
   }
   Map<String, SortedSet<String>> families = new TreeMap<>();
   Iterator<String> iterator= word.iterator();
   for (int i = 0; i < word.size(); i++) {
       String words = iterator.next();
       this.chosenWord = words;
       String pattern = this.getPattern();
       if (!families.containsKey(pattern)) {
           families.put(pattern, new TreeSet<>(word));
       }
       families.get(pattern).add(words);
   }
   int maxSize = 0;
   String maxPattern = "";
   for (String pattern : families.keySet()) {
       if (families.get(pattern).size() > maxSize) {
           maxSize = families.get(pattern).size();
           maxPattern = pattern;
       }
   }
   this.chosenWord = families.get(maxPattern).last();
   previousGuesses.add(letter);
   int count = 0;
   for (int i = 0; i < chosenWord.length(); i++) {
       if (chosenWord.charAt(i) == letter) {
           count++;
       }
   }
   if (count == 0) {
       guessesLeft--;
   }
   return count;
}