public function setup()
{
parent::setup();
// Remove post type support and meta boxes.
$this->remove_post_type_support();
// Add support for displaying information in publish box from a page type.
if (method_exists($this, 'publish_box')) {
add_action('post_submitbox_misc_actions', [$this, 'publish_box']);
}
// Hide page template dropdown if it shouldn't be showed.
if (!$this->show_page_template) {
add_filter('theme_page_templates', '__return_empty_array');
}
}