anchor.diff:      });
       test('1 and 2', () {
         var board = getEmptyBoard();
  +      //r
  +      //r r
         board[0] = new List.filled(1, Cell.red);
         board[1] = new List.filled(2, Cell.red);
         printBoard(board);
   
         int result = threeConnectedCount(board);
  -      expect(result, 1);
  +      expect(result, 4);
       });
       test('2 and 1', () {
         var board = getEmptyBoard();
  +      //r r
  +      //r
         board[0] = new List.filled(2, Cell.red);
         board[1] = new List.filled(1, Cell.red);
         printBoard(board);
   
         int result = threeConnectedCount(board);
  -      expect(result, 1);
  +      expect(result, 3);
       });
     });
   
  
positive.code:   group('connected colors:', () {
      test('empty board', () {
        var board = getEmptyBoard();
        Map<int, Set<Point>> result = connectedColors(board);
        expect(result.isEmpty, true);
      });
      test('1 pair', () {
        var board = getEmptyBoard();
        board[0] = new List.filled(1, Cell.red);
        board[1] = new List.filled(1, Cell.blue);
        Map<int, Set<Point>> result = connectedColors(board);
        expect(result.isEmpty, false);
        expect(result.keys.length, 2);
        expect(result[0].length, 1);
        expect(result[1].length, 1);
      });
    });
  
    group('validNeighbors:', () {
      test('empty board', () {
        var board = getEmptyBoard();
        var result = validNeighbors(new Point(0,0), board);
        expect(result.length, 0);
      });
      test('vertical pair', () {
        var board = getEmptyBoard();
        board[0] = new List.filled(2, Cell.red);
        var result = validNeighbors(new Point(0,0), board);
        expect(result.length, 1);
        result = validNeighbors(new Point(1,0), board);
        expect(result.length, 1);
      });
      test('horizontal pair', () {
        var board = getEmptyBoard();
        board[0] = new List.filled(1, Cell.red);
        board[1] = new List.filled(1, Cell.red);
        var result = validNeighbors(new Point(0,0), board);
        expect(result.length, 1);
        result = validNeighbors(new Point(0,1), board);
        expect(result.length, 1);
      });
      test('three neighbors', () {
        var board = getEmptyBoard();
        board[0] = new List.filled(1, Cell.red);
        board[1] = new List.filled(2, Cell.red);
        board[2] = new List.filled(1, Cell.red);
        var result = validNeighbors(new Point(0,0), board);
        expect(result.length, 1);
        result = validNeighbors(new Point(0,1), board);
        expect(result.length, 3);
        result = validNeighbors(new Point(0,2), board);
        expect(result.length, 1);
      });
      test('four neighbors', () {
        var board = getEmptyBoard();
  
negative.code:       board[0] = new List.filled(2, Cell.red);
        board[1] = new List.filled(3, Cell.red);
        board[2] = new List.filled(2, Cell.red);
        var result = validNeighbors(board, new Point(0,0));
        expect(result.length, 2);
        result = validNeighbors(board, new Point(1,0));
        expect(result.length, 3);
        result = validNeighbors(board, new Point(0,1));
        expect(result.length, 3);
        result = validNeighbors(board, new Point(1,1));
        expect(result.length, 4);
        result = validNeighbors(board, new Point(2,1));
        expect(result.length, 4);
        result = validNeighbors(board, new Point(0,2));
        expect(result.length, 3);
        result = validNeighbors(board, new Point(1,2));
        expect(result.length, 4);
      });
    });
  
  