frame.refresh();
assertNoErrors(frame);
HTMLTableInfo panel = (HTMLTableInfo) frame.getChildrenWidgets().get(0);
// prepare new Button, associate it with "panel"
WidgetInfo newButton = createButton();
panel.addChild(newButton);
// check CellConstraintsSupport
CellConstraintsSupport constraints = HTMLTableInfo.getConstraints(newButton);
assertEquals(-1, constraints.getX());
assertEquals(-1, constraints.getY());
assertEquals(1, constraints.getWidth());