14 files declare their use of GeneratedUrl in Drupal 8

EntityReferenceFieldItemNormalizerTest.php in core/modules/serialization/tests/src/Unit/Normalizer/EntityReferenceFieldItemNormalizerTest.php

EntityUrlTest.php in core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php

FieldPluginBaseTest.php in core/modules/views/tests/src/Unit/Plugin/field/FieldPluginBaseTest.php

Contains \Drupal\Tests\views\Unit\Plugin\field\FieldPluginBaseTest.

LinkGeneratorTest.php in core/tests/Drupal/Tests/Core/Utility/LinkGeneratorTest.php

LinkTest.php in core/modules/jsonapi/tests/src/Unit/JsonApiResource/LinkTest.php

MetadataBubblingUrlGenerator.php in core/lib/Drupal/Core/Render/MetadataBubblingUrlGenerator.php

RenderElementTest.php in core/tests/Drupal/Tests/Core/Render/Element/RenderElementTest.php

RequestFormatRouteFilterTest.php in core/tests/Drupal/Tests/Core/Routing/RequestFormatRouteFilterTest.php

RouteNoneTest.php in core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteNoneTest.php

RouteProcessorCurrentIntegrationTest.php in core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteProcessorCurrentIntegrationTest.php

UnroutedUrlAssembler.php in core/lib/Drupal/Core/Utility/UnroutedUrlAssembler.php

UnroutedUrlAssemblerTest.php in core/tests/Drupal/Tests/Core/Utility/UnroutedUrlAssemblerTest.php

UrlGenerator.php in core/lib/Drupal/Core/Routing/UrlGenerator.php

UrlTest.php in core/tests/Drupal/Tests/Core/UrlTest.php

Contains \Drupal\Tests\Core\UrlTest.