8 files declare their use of TemplateCollection in Courier 2.x

courier.module in ./courier.module

Hooks for Courier.

CourierGlobalCollectionEntityTest.php in tests/src/Kernel/CourierGlobalCollectionEntityTest.php

CourierManagerTest.php in tests/src/Kernel/CourierManagerTest.php

CourierTest.php in src/Tests/CourierTest.php

courier_system.install in courier_system/courier_system.install

Install functions for Courier system.

EmailForm.php in src/Form/EmailForm.php

GlobalTemplateCollectionManager.php in src/Service/GlobalTemplateCollectionManager.php

MessageForm.php in courier_message_composer/src/Form/MessageForm.php