anchor.diff:        directionSystem = null;
       });
       test("Get main directions", () {
  -      testGetDirections(directionSystem, Direction.MAIN_DIRECTIONS, 
  -          [{"x": 0,"y": -1}, {"x": 0,"y": 1}, 
  +      testGetDirections(directionSystem, Direction.MAIN_DIRECTIONS,
  +          [{"x": 0,"y": -1}, {"x": 0,"y": 1},
              {"x": -1,"y": 0}, {"x": 1,"y": 0}]);
       });
       test("Get diagonal directions", () {
  -      testGetDirections(directionSystem, Direction.DIAGONAL_DIRECTIONS, 
  -          [{"x": -expectedDiagonalValue,"y": -expectedDiagonalValue}, 
  -           {"x": expectedDiagonalValue,"y": -expectedDiagonalValue}, 
  +      testGetDirections(directionSystem, Direction.DIAGONAL_DIRECTIONS,
  +          [{"x": -expectedDiagonalValue,"y": -expectedDiagonalValue},
  +           {"x": expectedDiagonalValue,"y": -expectedDiagonalValue},
              {"x": -expectedDiagonalValue,"y": expectedDiagonalValue},
              {"x": expectedDiagonalValue,"y": expectedDiagonalValue}]);
       });
  
positive.code:     });
    });
  
  }
  
  //=============================================================================
  
negative.code:       directionSystem = null;
      });
      test("Testing diagonal directions", () {
        testSetMainDirection(directionSystem, Direction.MAIN_DIRECTIONS,
            [{"x": 0,"y": -1}, {"x": 0,"y": 1},
             {"x": -1,"y": 0}, {"x": 1,"y": 0}]);
      });
      test("Testing diagonal directions", () {
        testSetMainDirection(directionSystem, Direction.DIAGONAL_DIRECTIONS,
            [{"x": -expectedDiagonalValue,"y": -expectedDiagonalValue},
             {"x": expectedDiagonalValue,"y": -expectedDiagonalValue},
             {"x": -expectedDiagonalValue,"y": expectedDiagonalValue},
  