7 files declare their use of NullIncludedData

DefaultExceptionSubscriber.php in core/modules/jsonapi/src/EventSubscriber/DefaultExceptionSubscriber.php
EntityResource.php in core/modules/jsonapi/src/Controller/EntityResource.php
EntryPoint.php in core/modules/jsonapi/src/Controller/EntryPoint.php
FileUpload.php in core/modules/jsonapi/src/Controller/FileUpload.php
JsonApiDocumentTopLevelNormalizerTest.php in core/modules/jsonapi/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
JsonapiMaintenanceModeSubscriber.php in core/modules/jsonapi/src/EventSubscriber/JsonapiMaintenanceModeSubscriber.php
ResourceTestBase.php in core/modules/jsonapi/tests/src/Functional/ResourceTestBase.php

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