public class Blackjack{

    public int  parseCard(String card) {
        throw new UnsupportedOperationException("Please implement the Blackjack.parseCard method");
    }

    public boolean isBlackjack(String card1, String card2) {
        throw new UnsupportedOperationException("Please implement the Blackjack.isBlackjack method");
    }

    public String largeHand(boolean isBlackjack, int dealerScore) {
        throw new UnsupportedOperationException("Please implement the Blackjack.largeHand method");
    }

    public String smallHand(handScore int, dealerScore int) {
        throw new UnsupportedOperationException("Please implement the Blackjack.smallHand method");
    }

    // FirstTurn returns the semi-optimal decision for the first turn, given the cards of the player and the dealer.
    // This function is already implemented and does not need to be edited. It pulls the other functions together in a
    // complete decision tree for the first turn.
    public String  firstTurn(String card1, String card2, String dealerCard) {
        int handScore = parseCard(card1) + parseCard(card2);
        int dealerScore = parseCard(dealerCard);

        if (20 < handScore) 
            return largeHand(isBlackjack(card1, card2), dealerScore);
        
        else
            return smallHand(handScore, dealerScore);
    }
}

public class Blackjack{

    public int  parseCard(String card) {
        throw new UnsupportedOperationException("Please implement the Blackjack.parseCard method");
    }

    public boolean isBlackjack(String card1, String card2) {
        throw new UnsupportedOperationException("Please implement the Blackjack.isBlackjack method");
    }

    public String largeHand(boolean isBlackjack, int dealerScore) {
        throw new UnsupportedOperationException("Please implement the Blackjack.largeHand method");
    }

    public String smallHand(int handScore, int dealerScore) {
        throw new UnsupportedOperationException("Please implement the Blackjack.smallHand method");
    }

    // FirstTurn returns the semi-optimal decision for the first turn, given the cards of the player and the dealer.
    // This function is already implemented and does not need to be edited. It pulls the other functions together in a
    // complete decision tree for the first turn.
    public String firstTurn(String card1, String card2, String dealerCard) {
        int handScore = parseCard(card1) + parseCard(card2);
        int dealerScore = parseCard(dealerCard);

        if (20 < handScore) 
            return largeHand(isBlackjack(card1, card2), dealerScore);
        
        else
            return smallHand(handScore, dealerScore);
    }
}

Correct parameter types and names in smallHand() (#1979)