12 files declare their use of Plugin in Service Container 7

Block.php in lib/Drupal/Core/Block/Annotation/Block.php

Contains \Drupal\Core\Block\Annotation\Block.

Plugin1A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_test/src/Plugin/Plugin1/Plugin1A/Plugin1A.php

Plugin1B.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_test/src/Plugin/Plugin1/Plugin1B/Plugin1B.php

Plugin2A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_test/src/Plugin/Plugin2/Plugin2A/Plugin2A.php

Plugin2B.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_test/src/Plugin/Plugin2/Plugin2B/Plugin2B.php

Plugin3A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_test/src/Plugin/Plugin3/Plugin3A/Plugin3A.php

Plugin5A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_subtest/src/Plugin/Plugin5/Plugin5A/Plugin5A.php

Plugin5B.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_subtest/src/Plugin/Plugin5/Plugin5B/Plugin5B.php

Plugin6A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_subtest/src/Plugin/Plugin6/Plugin6A/Plugin6A.php

Plugin6B.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_subtest/src/Plugin/Plugin6/Plugin6B/Plugin6B.php

Plugin7A.php in modules/providers/service_container_annotation_discovery/tests/modules/service_container_annotation_discovery_subtest/src/Plugin/Plugin7/Plugin7A/Plugin7A.php

ServiceContainerBlock.php in modules/utility/service_container_block/src/Plugin/Block/ServiceContainerBlock.php

Contains \Drupal\service_container_block\Plugin\Block\ServiceContainerBlock.