12 files declare their use of QueryInterface in Drupal 9
- ConfigEntityStorageTest.php in core/tests/ Drupal/ Tests/ Core/ Config/ Entity/ ConfigEntityStorageTest.php 
- DrupalTest.php in core/tests/ Drupal/ Tests/ Core/ DrupalTest.php 
- EntityResource.php in core/modules/ jsonapi/ src/ Controller/ EntityResource.php 
- EntityStorageBase.php in core/lib/ Drupal/ Core/ Entity/ EntityStorageBase.php 
- Filter.php in core/modules/ jsonapi/ src/ Query/ Filter.php 
- ItemStorage.php in core/modules/ aggregator/ src/ ItemStorage.php 
- MakeUniqueEntityFieldTest.php in core/modules/ migrate/ tests/ src/ Unit/ process/ MakeUniqueEntityFieldTest.php 
- Query.php in core/lib/ Drupal/ Core/ Config/ Entity/ Query/ Query.php 
- Query.php in core/lib/ Drupal/ Core/ Entity/ Query/ Sql/ Query.php 
- Query.php in core/lib/ Drupal/ Core/ Entity/ Query/ Null/ Query.php 
- SqlContentEntityStorage.php in core/lib/ Drupal/ Core/ Entity/ Sql/ SqlContentEntityStorage.php 
- TemporaryQueryGuard.php in core/modules/ jsonapi/ src/ Access/ TemporaryQueryGuard.php 
