Around plugin for prepareTemplate method in Magento\Sales\Model\Order\Email\Sender abstract class?

Question

In Magento I can't override abstract class so I tried to use the around plugin. How can I do it for prepareTemplate method in Magento\Sales\Model\Order\Email\Sender abstract class? Right now I did some thing like this: di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Sales\Model\Order\Email\Sender">
        <plugin name="sale_order_sender_custom_email"
                type="Vendor\Module\Plugin\Magento\Sales\Model\Order\Email\SenderPlugin"
                sortOrder="1"/>
    </type>
</config>

SenderPlugin.php

<?php

namespace Vendor\Module\Plugin\Magento\Sales\Model\Order\Email;

use Closure;
use Magento\Sales\Model\Order;
use Magento\Sales\Model\Order\Email\Sender;
use Magento\Sales\Model\Order\Email\Container\IdentityInterface;
use Magento\Sales\Model\Order\Email\Container\Template;

class SenderPlugin
{

    public $templateContainer;
    public $identityContainer;

    public function __construct(
        Template $templateContainer,
        IdentityInterface $identityContainer
    )
    {
        $this->templateContainer = $templateContainer;
        $this->identityContainer = $identityContainer;
    }

    public function aroundPrepareTemplate(Sender $subject, Closure $proceed, Order $order)
    {
        $this->templateContainer->setTemplateOptions($this->getTemplateOptions());

        if ($order->getCustomerIsGuest()) {
            $templateId = $this->identityContainer->getGuestTemplateId();
            $customerName = $order->getBillingAddress()->getName();
        } else {
            $templateId = $this->identityContainer->getTemplateId();
            $customerName = $order->getCustomerName();
        }

        $this->identityContainer->setCustomerName($customerName);
        $this->identityContainer->setCustomerEmail($order->getCustomerEmail());
        $this->templateContainer->setTemplateId('custom_email_template');
    }

}

Answer 1

Were you able to fix this one? As much I recall, you cannot plugin a protected method.