/**
  * Retrieves the one true instance of Attribution_Analytics_WordPress
  *
  * @since  1.0.0
  * @return object Singleton instance of Attribution_Analytics_WordPress
  */
 public static function get_instance()
 {
     if (!isset(self::$instance) && !self::$instance instanceof Attribution_Analytics_WordPress) {
         self::$instance = new Attribution_Analytics_WordPress();
         self::$instance->load_textdomain();
         self::$instance->admin_hooks();
         self::$instance->frontend_hooks();
         self::$instance->analytics = Attribution_Analytics::get_instance();
         self::$instance->include_files();
     }
     return self::$instance;
 }