Created test class HandOfCardsTest, refactored class HandOfCards, implemented...

Created test class HandOfCardsTest, refactored class HandOfCards, implemented methods for calculating sum of values, implemented methods to check for specific cards, implemented JavaDocs for HandOfCards class.

src/main/java/edu/ntnu/idatt2003/HandOfCards.java

 package edu.ntnu.idatt2003;
 
-import java.util.List;
+import java.util.*;
+import java.util.stream.Collectors;
 
+/**
+ * A class representing a hand of cards.
+
+ */
 public class HandOfCards {
     private List<PlayingCard> hand;
 
+    /**
+     * Constructor for HandOfCards
+     * @param hand A list of PlayingCard objects
+     */
+
     public HandOfCards(List<PlayingCard> hand) {
         this.hand = hand;
     }
 
-    public boolean isFlush() {
-        if (hand.size() < 5) {
-            return false;
-        }
+    /**
+     * Method for calculating the sum of the face values of the cards in the hand
+     * @return The sum of the face values
+     */
+
+    public int sumOfCardValues() {
+        return hand.stream()
+                .mapToInt(PlayingCard::getFace)
+                .sum();
+    }
+
+    /**
+     * Method for finding all the hearts in the hand
+     * @return A string containing the hearts in the hand
+     */
+    public String heartsOnHand() {
+        String hearts = hand.stream()
+                .filter(card -> card.getSuit() == 'H')
+                .map(PlayingCard::getAsString)
+                .collect(Collectors.joining(" "));
+        return hearts.isEmpty() ? "No Hearts" : hearts;
+    }
+
+    /**
+     * Method for checking if the hand contains the queen of spades
+     * @return True if the hand contains the queen of spades, false otherwise
+     */
+    public boolean hasQueenOfSpades() {
+        return hand.stream()
+                .anyMatch(card -> card.getSuit() == 'S' && card.getFace() == 12);
+    }
 
-        return false;
+    /**
+     * Method for checking if the hand contains a flush
+     * @return True if the hand contains a flush, false otherwise
+     */
+    public boolean isFiveFlush() {
+        return hand.stream()
+                .collect(Collectors.groupingBy(PlayingCard::getSuit, Collectors.counting()))
+                .values()
+                .stream()
+                .anyMatch(count -> count >= 5);
+    }
+    /**
+     * Method for returning the hand as a string
+     * @return A string representation of the hand
+     */
+    @Override
+    public String toString() {
+        return hand.stream()
+                .map(PlayingCard::getAsString)
+                .collect(Collectors.joining(" "));
     }
 }
+