6 files declare their use of FieldUiTestTrait in Zircon Profile 8

CommentNonNodeTest.php in core/modules/comment/src/Tests/CommentNonNodeTest.php

Contains \Drupal\comment\Tests\CommentNonNodeTest.

ContactSitewideTest.php in core/modules/contact/src/Tests/ContactSitewideTest.php

Contains \Drupal\contact\Tests\ContactSitewideTest.

EntityReferenceAdminTest.php in core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php

Contains \Drupal\field\Tests\EntityReference\EntityReferenceAdminTest.

FileFieldWidgetTest.php in core/modules/file/src/Tests/FileFieldWidgetTest.php

Contains \Drupal\file\Tests\FileFieldWidgetTest.

LinkFieldUITest.php in core/modules/link/src/Tests/LinkFieldUITest.php

Contains \Drupal\link\Tests\LinkFieldUITest.

ResponsiveImageFieldUiTest.php in core/modules/responsive_image/src/Tests/ResponsiveImageFieldUiTest.php

Contains \Drupal\responsive_image\Tests\ResponsiveImageFieldUiTest.