Load the attached fxml :
although the control width (pref, max, min) is USE_COMPUTED_SIZE, the width is not controlled by its container.
(height should be also checked)
This is a regression compared to 2.2, where this test case works perfectly well (i.e. the width is controlled by the container)
 Note that even if the prefWidth is bigger than the container one, the width should be the container width.