Controls whether or not the default display should have its own tab on edit.
public function isDefaultDisplayShown(ViewUI $view) {
// Always show the default display for advanced users who prefer that mode.
$advanced_mode = config('views.settings')
->get('ui.show.master_display');
// For other users, show the default display only if there are no others, and
// hide it if there's at least one "real" display.
$additional_displays = count($view
->get('executable')->displayHandlers) == 1;
return $advanced_mode || $additional_displays;
}