Label button = new Label("open-endless-modal", "Open Modal Dialog");
modal.addOpenerAttributesTo(button);
add(modal, button);
// issue #93
add(new Label("popover", "Popover (hover, top)").add(new PopoverBehavior(
Model.of("title"),
Model.of("content"),
new PopoverConfig().withHoverTrigger().withPlacement(TooltipConfig.Placement.top)
)));