Opis\Closure\SerializableClosure::exitContext PHP Method

    public static function exitContext()
    {
        if (static::$context !== null && !--static::$context->locks) {
            static::$context = null;
        }
    }

 public function serialize()
 {
     SerializableClosure::enterContext();
     $object = $this->mapFunction1($this->variables);
     SerializableClosure::exitContext();
     return serialize($object);
 }