 
   func testMerge7() {
     // Scenario: multiple spaces and merges
-    let m = GameModel(dimension: 5, threshold: 2048)
+    let m = GameModel(dimension: 5, threshold: 2048, delegate: self)
     let group = [TileObject.Empty,
       TileObject.Tile(value: 2),
       TileObject.Tile(value: 2),

  }

  func testCondense4() {
    let m = GameModel(dimension: 5, threshold: 2048)
    let group = [TileObject.Tile(value: 2),
      TileObject.Tile(value: 2),
      TileObject.Tile(value: 16),


  func testMerge2() {
    // Scenario: some moves
    let m = GameModel(dimension: 5, threshold: 2048, delegate: self)
    var group = [TileObject.Tile(value: 1),
      TileObject.Empty,
      TileObject.Tile(value: 4),
