/** * Check quote amount * * @param \Magento\Sales\Model\Quote $quote * @param float $amount * @return $this */ public function checkQuoteAmount(\Magento\Sales\Model\Quote $quote, $amount) { if (!$quote->getHasError() && $amount >= self::MAXIMUM_AVAILABLE_NUMBER) { $quote->setHasError(true); $quote->addMessage(__('This item price or quantity is not valid for checkout.')); } return $this; }