tController.sheet.trait;
    if (sheetTrait !== null) {
      sheetView.appendChild("h2").set({
        style: {
          margin: 12,
          cursor: "pointer",
          userSelect: "none",
        },
        text: sheetTrait.title.value,
      });
    }
  },
})]);

const stackController = new ExampleStackController();
stackController.mount();
stackController.stack.attachView().style.set({
  flexGrow: 1,
});

const navBarController = stackController.navBar.insertController();
navBarController.closeButto