6 files declare their use of Newsletter in Simplenews 8

simplenews.install in ./simplenews.install

Install, update and uninstall functions for the simplenews module

SimplenewsAdministrationTest.php in src/Tests/SimplenewsAdministrationTest.php

SimplenewsI18nTest.php in src/Tests/SimplenewsI18nTest.php

SimplenewsTestBase.php in src/Tests/SimplenewsTestBase.php

Simplenews test functions.

simplenews_demo.install in modules/simplenews_demo/simplenews_demo.install

Simplenews_demo base install file.

SubscriptionsFormBase.php in src/Form/SubscriptionsFormBase.php