anchor.diff:      beforeEach(() {
         transformer = new HtmlInspector(new StitchSpriteSheetEngine(), new StitchAssetProvider());
         primaryInput = new Mock()
  -          ..when(callsTo("get id")).alwaysReturn(new AssetId("my_package", "index.html"));
  +          ..when(callsTo("get id")).alwaysReturn(new AssetId("my_package", "web/index.html"));
         transform = new TransformMock()
             ..when(callsTo("get primaryInput")).alwaysReturn(primaryInput)
             ..when(callsTo("get logger")).alwaysReturn(new TransformLogger((id, level, message, span) {}));
  
positive.code:     describe("when provider returns list of assets", () {
        beforeEach(() => buildTransformer(
            htmlWithCss,
            assets: [createAsset("images/icons/info.png"), createAsset("images/icons/star.png")],
            spriteSheet: new SpriteSheet("spritesheet", [
              new Sprite("info.png", new Image(100, 100), new Point(0, 0)),
              new Sprite("star.png", new Image(100, 100), new Point(0, 100))
            ])));
  
        it("adds an output for images/icons.css", () {
          transformer.apply(transform).then(expectAsync((_) {
            var expectation = _expectAsset(new AssetId("my_package", "images/icons.css"));
            transform.getLogs(callsTo("addOutput", expectation)).verify(happenedOnce);
          }));
        });
  
        it("adds an output for images/icons.png", () {
          transformer.apply(transform).then(expectAsync((_) {
            var expectation = _expectAsset(new AssetId("my_package", "images/icons.png"));
            transform.getLogs(callsTo("addOutput", expectation)).verify(happenedOnce);
          }));
        });
  
negative.code: 
        it("requests provider for assets", () {
          transformer.apply(transform).then(expectAsync((_) => provider
              .getLogs(callsTo("call", new AssetId("my_package", "web/images/icons.css")))
              .verify(happenedOnce)));
        });
      });
  