17 files declare their use of Block in Zircon Profile 8

AreaEntityTest.php in core/modules/views/src/Tests/Handler/AreaEntityTest.php

Contains \Drupal\views\Tests\Handler\AreaEntityTest.

AreaEntityUITest.php in core/modules/views_ui/src/Tests/AreaEntityUITest.php

Contains \Drupal\views_ui\Tests\AreaEntityUITest.

block.module in core/modules/block/block.module

Controls the visual building blocks a page is constructed with.

BlockConfigSchemaTest.php in core/modules/block/src/Tests/BlockConfigSchemaTest.php

Contains \Drupal\block\Tests\BlockConfigSchemaTest.

BlockContextMappingUpdateTest.php in core/modules/block/src/Tests/Update/BlockContextMappingUpdateTest.php

Contains \Drupal\block\Tests\Update\BlockContextMappingUpdateTest.

BlockInvalidRegionTest.php in core/modules/block/src/Tests/BlockInvalidRegionTest.php

Contains \Drupal\block\Tests\BlockInvalidRegionTest.

BlockLanguageTest.php in core/modules/block/src/Tests/BlockLanguageTest.php

Contains \Drupal\block\Tests\BlockLanguageTest.

BlockStorageUnitTest.php in core/modules/block/src/Tests/BlockStorageUnitTest.php

Contains \Drupal\block\Tests\BlockStorageUnitTest.

BlockTest.php in core/modules/block/src/Tests/BlockTest.php

Contains \Drupal\block\Tests\BlockTest.

BlockViewBuilderTest.php in core/modules/block/src/Tests/BlockViewBuilderTest.php

Contains \Drupal\block\Tests\BlockViewBuilderTest.

EntityCrudHookTest.php in core/modules/system/src/Tests/Entity/EntityCrudHookTest.php

Contains \Drupal\system\Tests\Entity\EntityCrudHookTest.

LanguageUILanguageNegotiationTest.php in core/modules/language/src/Tests/LanguageUILanguageNegotiationTest.php

Contains \Drupal\language\Tests\LanguageUILanguageNegotiationTest.

MenuTest.php in core/modules/menu_ui/src/Tests/MenuTest.php

Contains \Drupal\menu_ui\Tests\MenuTest.

MigrateBlockTest.php in core/modules/block/src/Tests/Migrate/d6/MigrateBlockTest.php

Contains \Drupal\block\Tests\Migrate\d6\MigrateBlockTest.

MigrateBlockTest.php in core/modules/block/src/Tests/Migrate/d7/MigrateBlockTest.php

Contains \Drupal\block\Tests\Migrate\d7\MigrateBlockTest.

NodeBlockFunctionalTest.php in core/modules/node/src/Tests/NodeBlockFunctionalTest.php

Contains \Drupal\node\Tests\NodeBlockFunctionalTest.

WebTestBase.php in core/modules/simpletest/src/WebTestBase.php

Contains \Drupal\simpletest\WebTestBase.