13 files declare their use of VocabularyInterface

forum.module in core/modules/forum/forum.module
Provides discussion forums.
ForumUninstallValidator.php in core/modules/forum/src/ForumUninstallValidator.php
MigrateTaxonomyVocabularyTest.php in core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyVocabularyTest.php
Overview.php in core/modules/forum/src/Form/Overview.php
OverviewTerms.php in core/modules/taxonomy/src/Form/OverviewTerms.php
taxonomy.module in core/modules/taxonomy/taxonomy.module
Enables the organization of content into categories.
TaxonomyController.php in core/modules/taxonomy/src/Controller/TaxonomyController.php
TaxonomyLegacyTest.php in core/modules/taxonomy/tests/src/Kernel/TaxonomyLegacyTest.php
TaxonomyTestTrait.php in core/modules/taxonomy/tests/src/Traits/TaxonomyTestTrait.php
taxonomy_crud.module in core/modules/taxonomy/tests/modules/taxonomy_crud/taxonomy_crud.module
Provides hook implementations for testing purposes.
Vocabulary.php in core/modules/taxonomy/src/Entity/Vocabulary.php
VocabularyResponse.php in core/modules/taxonomy/tests/modules/vocabulary_serialization_test/src/VocabularyResponse.php
VocabularySerializationTestController.php in core/modules/taxonomy/tests/modules/vocabulary_serialization_test/src/VocabularySerializationTestController.php

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