Specify the Deck type (part of the posted HighLow Java program). Give the rep invariant and abstraction function. Implement the repOk method.

public class Deck { /** * An array of 52 or 54 cards. A 54-card deck contains two Jokers, * in addtion to the 52 cards of a regular poker deck. */ private Card[] deck; /** * Keeps track of the number of cards that have been dealt from * the deck so far. */ private int cardsUsed; /** * Constructs a regular 52-card poker deck. Initially, the cards * are in a sorted order. The shuffle() method can be called to * randomize the order. (Note that "new Deck()" is equivalent * to "new Deck(false)".) */ public Deck() { this(false); // Just call the other constructor in this class. } /** * Constructs a poker deck of plaing cards, The deck contains * the ususal 52 cards and can optionally contain two Jokers * in addtion, for a total of 54 cards. Initially the cards * are in a sorted order. The shuffle() method can be called to * randomize the order. * @param includeJokers if true, two Jokers are included in the deck; if false, * there are no Jokers in the deck. */ public Deck(boolean includeJokers) { if (includeJokers) deck = new Card[54]; else deck = new Card[52]; int cardCt = 0; // How many cards have been created so far. for ( int suit = 0; suit <= 3; suit++ ) { for ( int value = 1; value <= 13; value++ ) { deck[cardCt] = new Card(value,suit); cardCt++; } } if (includeJokers) { deck[52] = new Card(1,Card.JOKER); deck[53] = new Card(2,Card.JOKER); } cardsUsed = 0; } /** * Put all the used cards back into the deck (if any), and * shuffle the deck into a random order. */ public void shuffle() { for ( int i = deck.length-1; i > 0; i-- ) { int rand = (int)(Math.random()*(i+1)); Card temp = deck[i]; deck[i] = deck[rand]; deck[rand] = temp; } cardsUsed = 0; } /** * As cards are dealt from the deck, the number of cards left * decreases. This function returns the number of cards that * are still left in the deck. The return value would be * 52 or 54 (depending on whether the deck includes Jokers) * when the deck is first created or after the deck has been * shuffled. It decreases by 1 each time the dealCard() method * is called. */ public int cardsLeft() { return deck.length - cardsUsed; } /** * Removes the next card from the deck and return it. It is illegal * to call this method if there are no more cards in the deck. You can * check the number of cards remaining by calling the cardsLeft() function. * @return the card which is removed from the deck. * @throws IllegalStateException if there are no cards left in the deck */ public Card dealCard() { if (cardsUsed == deck.length) throw new IllegalStateException("No cards are left in the deck."); cardsUsed++; return deck[cardsUsed - 1]; // Programming note: Cards are not literally removed from the array // that represents the deck. We just keep track of how many cards // have been used. } /** * Test whether the deck contains Jokers. * @return true, if this is a 54-card deck containing two jokers, or false if * this is a 52 card deck that contains no jokers. */ public boolean hasJokers() { return (deck.length == 54); } } // end class Deck