6 files declare their use of AbstractEventVariables in Hook Event Dispatcher 3.x

AbstractPreprocessEvent.php in modules/preprocess_event_dispatcher/src/Event/AbstractPreprocessEvent.php

ExampleEventVariables.php in examples/preprocess_example_module/src/Variables/ExampleEventVariables.php

FakeEventVariables.php in modules/preprocess_event_dispatcher/tests/src/Unit/Helpers/FakeEventVariables.php

OtherEventVariablesTest.php in modules/preprocess_event_dispatcher/tests/src/Unit/OtherEventVariablesTest.php

PreprocessEntityEventInterface.php in modules/preprocess_event_dispatcher/src/Event/PreprocessEntityEventInterface.php

PreprocessEventInterface.php in modules/preprocess_event_dispatcher/src/Event/PreprocessEventInterface.php