public function _tracking()
 {
     include_once dirname(__FILE__) . '/inc/tracking.php';
     $tracking = Redux_Tracking::get_instance();
     $tracking->load($this);
 }

 private function _tracking()
 {
     require_once dirname(__FILE__) . '/inc/tracking.php';
     $tracking = Redux_Tracking::get_instance();
     $tracking->load($this);
 }

 private function _tracking()
 {
     if (file_exists(get_template_directory() . '/framework/theme-panel/ReduxCore/inc/tracking.php')) {
         require_once get_template_directory() . '/framework/theme-panel/ReduxCore/inc/tracking.php';
         $tracking = Redux_Tracking::get_instance();
         $tracking->load($this);
     }
 }

 /**
  * Creates or returns an instance of this class.
  *
  * @return  Foo A single instance of this class.
  */
 public static function get_instance()
 {
     if (null == self::$instance) {
         self::$instance = new self();
     }
     return self::$instance;
 }