drupal/core/modules/simpletest/simpletest.local_tasks.yml

simpletest.test_form:
  title: List
  route_name: simpletest.test_form
  base_route: simpletest.test_form
simpletest.settings:
  title: Settings
  route_name: simpletest.settings
  base_route: simpletest.test_form
  weight: 100