/**
  * Get Instance
  * Get AvadaReduxFrameworkInstances instance
  * OR an instance of AvadaReduxFramework by [opt_name]
  *
  * @param  string $opt_name the defined opt_name
  *
  * @return object                class instance
  */
 public static function get_instance($opt_name = false)
 {
     if (is_null(self::$instance)) {
         self::$instance = new self();
     }
     if ($opt_name && !empty(self::$instances[$opt_name])) {
         return self::$instances[$opt_name];
     }
     return self::$instance;
 }