$this->create_cpt('product', 'Products', 'Product', false, 'product');

$this->create_taxonomy('surface', 'product', __('Surface'), __('Surfaces'));
$this->create_taxonomy('products', 'product', __('Related Product'), __('Related Products'));

function create_taxonomy($tax, $post_type, $singular_name, $plural_name, $hierarchical = true, $show_ui = true) {
            $labels = array(
                'name' => _x( $plural_name, 'taxonomy general name' ),
                'singular_name' => __( $singular_name, 'taxonomy singular name' ),
                'search_items' =>  __( 'Search ' . $plural_name ),
                'all_items' => __( 'All ' . $plural_name ),
                'parent_item' => __( 'Parent ' . $singular_name ),
                'parent_item_colon' => __( 'Parent ' . $singular_name . ':' ),
                'edit_item' => __( 'Edit ' . $singular_name ),
                'update_item' => __( 'Update ' . $singular_name ),
                'add_new_item' => __( 'Add New ' . $singular_name ),
                'new_item_name' => __( 'New ' . $singular_name . ' Name' ),
            );

            $args = array(
                'hierarchical' => $hierarchical,
                'labels' => $labels,
                'show_ui' => $show_ui
            );

            register_taxonomy( $tax, $post_type, $args);

        }

function create_cpt($post_type, $plural_name, $singular_name, $hierarchical = false, $slug = '', $capability = 'post', $menu_position = 5, $supports = array('title','editor','excerpt','thumbnail','custom-fields')) {
            $labels = array(
                'name' => __($plural_name, 'post type general name'),
                'singular_name' => __($singular_name, 'post type singular name'),
                'add_new' => __('Add new ' . $singular_name, $post_type),
                'add_new_item' => __('Add new ' . $singular_name),
                'edit_item' => __('Edit ' . $plural_name),
                'new_item' => __('New ' . $singular_name),
                'view_item' => __('View ' . $singular_name),
                'search_items' => __('Search ' . $plural_name),
                'not_found' =>  __('No ' . $plural_name . ' found'),
                'not_found_in_trash' => __('No ' . $plural_name . ' found in Trash'),
                'parent_item_colon' => ''
            );

            $args = array(
                'labels' => $labels,
                'public' => true,
                'publicly_queryable' => true,
                'show_ui' => true,
                '_builtin' => false,
                'query_var' => true,
                'hierarchical' => $hierarchical,
                'rewrite' => !empty($slug) ? array('slug' => $slug) : false,
                'capability_type' => $capability,
                'menu_position' => $menu_position,
                'supports' => $supports
            );

            register_post_type($post_type, $args);
        }