23 files declare their use of CommentInterface

comment.api.php in core/modules/comment/comment.api.php
Hooks provided by the Comment module.
Comment.php in core/modules/comment/src/Entity/Comment.php
CommentAdminOverview.php in core/modules/comment/src/Form/CommentAdminOverview.php
CommentBaseFieldTest.php in core/modules/comment/tests/src/Kernel/CommentBaseFieldTest.php
CommentCacheTagsTest.php in core/modules/comment/tests/src/Functional/CommentCacheTagsTest.php
CommentController.php in core/modules/comment/src/Controller/CommentController.php
CommentCSSTest.php in core/modules/comment/tests/src/Functional/CommentCSSTest.php
CommentDefaultFormatterCacheTagsTest.php in core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
CommentDisplayConfigurableTest.php in core/modules/comment/tests/src/Functional/CommentDisplayConfigurableTest.php
CommentLinksTest.php in core/modules/comment/tests/src/Functional/CommentLinksTest.php
CommentNameConstraintValidator.php in core/modules/comment/src/Plugin/Validation/Constraint/CommentNameConstraintValidator.php
CommentNonNodeTest.php in core/modules/comment/tests/src/Functional/CommentNonNodeTest.php
CommentSelection.php in core/modules/comment/src/Plugin/EntityReferenceSelection/CommentSelection.php
CommentTestBase.php in core/modules/comment/tests/src/Functional/CommentTestBase.php
CommentTestController.php in core/modules/comment/tests/modules/comment_test/src/Controller/CommentTestController.php
CommentTestHooks.php in core/modules/comment/tests/modules/comment_test/src/Hook/CommentTestHooks.php
CommentValidationTest.php in core/modules/comment/tests/src/Kernel/CommentValidationTest.php
DefaultViewRecentCommentsTest.php in core/modules/comment/tests/src/Functional/Views/DefaultViewRecentCommentsTest.php
DefaultViewsTest.php in core/modules/views/tests/src/Functional/DefaultViewsTest.php
EntityFilteringThemeTest.php in core/modules/system/tests/src/Functional/Theme/EntityFilteringThemeTest.php
EntityReferenceSelectionAccessTest.php in core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
NodeAccessPagerTest.php in core/modules/node/tests/src/Functional/NodeAccessPagerTest.php
UserCancelTest.php in core/modules/user/tests/src/Functional/UserCancelTest.php

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