magento2 – How to override a method of a class where the method itself is defined in its parent class, and only called in the current class?

I would like to extend the OrderSender class, located at MagentoSalesModelOrderEmailSender and then override the method prepareTemplate($order), this method is actually defined in the Sender class which is located at MagentoSalesModelOrderEmail and only called at OrderSender class as parent::prepareTemplate($order); because the OrderSender class extends Sender, class.

Now how can I override the prepareTemplate($order) method in the OrderSender class which is not defined here but just called?

Note: I don’t want to extend its parent class (Sender ) and override the method.