public function load_methods()
 {
     $active_methods = get_shipping_methods();
     foreach ($active_methods as $key => $method) {
         if ($method['supported']) {
             $class = 'SLP_' . strtoupper($key);
             if (!class_exists($class)) {
                 include_once $method['file'];
             }
             $this->methods[$key] = new $class();
         }
     }
 }
 /**
  * Ajax function _construct
  *
  * hook ajax callback functions
  * @return void
  */
 public function __construct()
 {
     $methods = get_shipping_methods();
     foreach ($methods as $key => $method) {
         $class = 'SLP_' . strtoupper($key);
         if (!class_exists($class)) {
             self::$carriers['key'] = $class;
         }
     }
     //ajax callback functions
     $ajax_functions = array('process_shipment', 'schedule_pickup', 'edit_address', 'get_shipments', 'void_shipment', 'track_shipment', 'track_history', 'update_pickup', 'update_shipments', 'get_packing_slip', 'get_labels', 'get_states', 'get_rates', 'repack_html', 'reset_order');
     //Hook ajax callback functions
     foreach ($ajax_functions as $ajax_function) {
         add_action('wp_ajax_' . $ajax_function, array($this, $ajax_function));
     }
 }