9 files declare their use of FieldUnitTestBase

EmailItemTest.php in drupal/core/modules/email/lib/Drupal/email/Tests/EmailItemTest.php: Contains \Drupal\email\Tests\EmailItemTest.
EntityReferenceItemTest.php in drupal/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceItemTest.php: Contains \Drupal\entity_reference\Tests\EntityReferenceItemTest.
FileItemTest.php in drupal/core/modules/file/lib/Drupal/file/Tests/FileItemTest.php: Contains \Drupal\file\Tests\FileItemTest.
ImageItemTest.php in drupal/core/modules/image/lib/Drupal/image/Tests/ImageItemTest.php: Contains \Drupal\image\Tests\ImageItemTest.
LinkItemTest.php in drupal/core/modules/link/lib/Drupal/link/Tests/LinkItemTest.php: Contains \Drupal\link\Tests\LinkItemTest.
NumberItemTest.php in drupal/core/modules/number/lib/Drupal/number/Tests/NumberItemTest.php: Contains \Drupal\number\Tests\NumberItemTest.
OptionsFieldUnitTestBase.php in drupal/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUnitTestBase.php: Contains \Drupal\options\Tests\OptionsFieldUnitTestBase.
TaxonomyTermReferenceItemTest.php in drupal/core/modules/taxonomy/lib/Drupal/taxonomy/Tests/TaxonomyTermReferenceItemTest.php: Contains \Drupal\taxonomy\Tests\TaxonomyTermReferenceItemTest.
TelephoneItemTest.php in drupal/core/modules/telephone/lib/Drupal/telephone/Tests/TelephoneItemTest.php: Contains \Drupal\field\Tests\TelephoneItemTest.