i tried to make the hang man game step by step on netbeans but it doesnt let me play...

public Game(String answer){
    mAnswer = answer;
    mHits = "";
    mMisses = "";
}

private char validateGuess(char letter){
    if(!Character.isLetter(letter)){
        throw new IllegalArgumentException("A letter is required");
    }
    letter = Character.toLowerCase(letter);
    if(mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >=0){
        throw new 
        IllegalArgumentException(letter + "had already been guessed");
    }
    return letter;
}

public boolean applyGuess(String letters){
    if(letters.length() == 0){
        throw new IllegalArgumentException("No letter found");
    }
    return applyGuess(letters.charAt(0));
}

public boolean applyGuess(char letter){
    letter = validateGuess(letter);
    boolean isHit = mAnswer.indexOf(letter) >= 0;
    if(isHit){
        mHits += letter;
    }
    else{
        mMisses += letter;
    }
    return isHit;
}

public String getCurrentProgress(){
    String progress = "";
    for(char letter : mAnswer.toCharArray()){
        char display = '-';
        if(mHits.indexOf(letter) >= 0){
            display = letter;
        }
        progress += display;
    }
    return progress;
}

public int getRemainingTries(){
    return MAX_MISSES - mMisses.length();
}

public String getAnswer(){
    return mAnswer;
}

public boolean isSolved(){
    return getCurrentProgress().indexOf('-') == -1;
}

public Prompter(Game game){
    mGame = game;
}

public void play(){
    while(mGame.getRemainingTries() > 0 && !mGame.isSolved()){
        displayProgress();
        promptForGuess();
    }
    if(mGame.isSolved()){
        System.out.printf("Congratulations you won with %d tries left.\n",
                           mGame.getRemainingTries());
    } else {
        System.out.printf("Bummer the word was, %s  :(",mGame.getAnswer());
    }
}

public boolean promptForGuess(){
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while(!isValidGuess){
    String guessAsString = console.readLine("Enter a letter: ");
    try{
        isHit =  mGame.applyGuess(guessAsString);
        isValidGuess = true;
    }catch (IllegalArgumentException iae){
        console.printf("%s. Please try again.\n",iae.getMessage());
    }
    }//while 
    return isHit;
}

public void displayProgress(){
    System.out.printf("You have %d tries left to solve: %s",
                       mGame.getRemainingTries(),
                       mGame.getCurrentProgress());
}