10 files declare their use of EntityHierarchyTestTrait in Entity Reference Hierarchy 3.x

BreadcrumbFunctionalTest.php in modules/entity_hierarchy_breadcrumb/tests/src/Functional/BreadcrumbFunctionalTest.php

DeleteParentWarningTest.php in tests/src/Functional/DeleteParentWarningTest.php

EntityHierarchyKernelTestBase.php in tests/src/Kernel/EntityHierarchyKernelTestBase.php

ForwardRevisionNodeValidationTest.php in tests/src/Functional/ForwardRevisionNodeValidationTest.php

HideWeightFieldFunctionalTest.php in tests/src/Functional/HideWeightFieldFunctionalTest.php

ManageDisplayTest.php in tests/src/Functional/ManageDisplayTest.php

MicrositeFunctionalTestBase.php in modules/entity_hierarchy_microsite/tests/src/Functional/MicrositeFunctionalTestBase.php

ReorderChildrenContentModerationFunctionalTest.php in tests/src/Functional/ReorderChildrenContentModerationFunctionalTest.php

ReorderChildrenFunctionalTest.php in tests/src/Functional/ReorderChildrenFunctionalTest.php

ReorderChildrenWithRevisionsFunctionalTest.php in tests/src/Functional/ReorderChildrenWithRevisionsFunctionalTest.php