Model/Config/Source/Transactional/Email/Template.php
public function toOptionArray()
    {
        /** @var $collection \Magento\Email\Model\ResourceModel\Template\Collection */
        if (!($collection = $this->coreRegistry->registry('config_system_email_template'))) {
            $collection = $this->templatesFactory->create();
            $collection->load();
            $this->coreRegistry->register('config_system_email_template', $collection);
        }
        return $this->emailConfig->getAvailableTemplates();
    }
public function toOptionArray()
    {
        /** @var $collection \Magento\Email\Model\ResourceModel\Template\Collection */
        if (!($collection = $this->coreRegistry->registry('config_system_email_template'))) {
            $collection = $this->templatesFactory->create();
            $collection->load();
            $this->coreRegistry->register('config_system_email_template', $collection);
        }
        return $this->emailConfig->getAvailableTemplates();
    }
public function toOptionArray ( ) { /** @var $collection \Magento\Email\Model\ResourceModel\Template\Collection */ if ( ! ( $ collection = $ this -> coreRegistry -> registry ( 'config_system_email_template' ) ) ) { $ collection = $ this -> templatesFactory -> create ( ) ; $ collection -> load ( ) ; $ this -> coreRegistry -> register ( 'config_system_email_template' , $ collection ) ; } return $ this -> emailConfig -> getAvailableTemplates ( ) ; }
Generate list of email templates

@return array
Generate list of email templates