added equals method for Board with test

src/main/java/Game/TicTacToe/Board.java

@@ -34,6 +34,8 @@ public class Board {
         }
     }
 
+
+
     /*
     1    ║2    ║3
       o  ║  x  ║  o
@@ -63,4 +65,18 @@ public class Board {
     public State[] getStates() {
         return this.states;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof Board)) {
+            return false;
+        }
+        Board x = (Board)o;
+        for (int i = 0; i < x.getStates().length; i++) {
+            if (this.getStates()[i] != x.getStates()[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
 }

src/test/java/Game/TicTacToe/BoardTest.java

@@ -35,5 +35,15 @@ class BoardTest {
     }
 
 
-
+    @SuppressWarnings("AssertBetweenInconvertibleTypes")
+    @Test
+    void testEquals() {
+        assertNotEquals(board, "Test");
+        Board secondBoard = new Board();
+        assertEquals(board, secondBoard);
+        secondBoard.getStates()[0] = Board.State.CROSS;
+        assertNotEquals(board, secondBoard);
+        board.getStates()[0] = Board.State.CROSS;
+        assertEquals(board, secondBoard);
+    }
 }