mapdev\FacebookMessenger\Callback\EntryMessage::updateDelivered PHP Method

    private function updateDelivered()
    {
        $this->isDelivered = !is_null(Helper::array_find($this->_message, 'delivery'));
        if ($this->isDelivered) {
            $this->delivery = new Delivered(Helper::array_find($this->_message, 'delivery'), $this->useCarbonDT);
        }
    }