public static function post_type_labels( $singular, $plural ) {
		$labels = apply_filters( 'popmake_popup_labels', array(
			'name'               => '%2$s',
			'singular_name'      => '%1$s',
			'add_new_item'       => _x( 'Create New %1$s', 'Post Type Singular: "Popup", "Popup Theme"', 'popup-maker' ),
			'add_new'            => _x( 'Create %1$s', 'Post Type Singular: "Popup", "Popup Theme"', 'popup-maker' ),
			'edit_item'          => _x( 'Edit %1$s', 'Post Type Singular: "Popup", "Popup Theme"', 'popup-maker' ),
			'new_item'           => _x( 'New %1$s', 'Post Type Singular: "Popup", "Popup Theme"', 'popup-maker' ),
			'all_items'          => _x( 'All %2$s', 'Post Type Plural: "Popups", "Popup Themes"', 'popup-maker' ),
			'view_item'          => _x( 'View %1$s', 'Post Type Singular: "Popup", "Popup Theme"', 'popup-maker' ),
			'search_items'       => _x( 'Search %2$s', 'Post Type Plural: "Popups", "Popup Themes"', 'popup-maker' ),
			'not_found'          => _x( 'No %2$s found', 'Post Type Plural: "Popups", "Popup Themes"', 'popup-maker' ),
			'not_found_in_trash' => _x( 'No %2$s found in Trash', 'Post Type Plural: "Popups", "Popup Themes"', 'popup-maker' ),
		) );

		foreach ( $labels as $key => $value ) {
			$labels[ $key ] = sprintf( $value, $singular, $plural );
		}

		return $labels;
	}