12 files declare their use of RequirementsPageTrait

DbUpdatesTrait.php in core/modules/system/tests/src/Functional/Update/DbUpdatesTrait.php
InstallerTestBase.php in core/modules/simpletest/src/InstallerTestBase.php
InstallerTestBase.php in core/tests/Drupal/FunctionalTests/Installer/InstallerTestBase.php
InvalidUpdateHookTest.php in core/modules/system/tests/src/Functional/UpdateSystem/InvalidUpdateHookTest.php
LocaleTranslatedSchemaDefinitionTest.php in core/modules/locale/tests/src/Functional/LocaleTranslatedSchemaDefinitionTest.php
MinimalTest.php in core/profiles/minimal/tests/src/Functional/MinimalTest.php
NoPreExistingSchemaUpdateTest.php in core/modules/system/tests/src/Functional/UpdateSystem/NoPreExistingSchemaUpdateTest.php
StandardTest.php in core/profiles/standard/tests/src/Functional/StandardTest.php
UpdateCacheTest.php in core/modules/system/tests/src/Functional/UpdateSystem/UpdateCacheTest.php
UpdateSchemaTest.php in core/modules/system/tests/src/Functional/UpdateSystem/UpdateSchemaTest.php
UpdateScriptTest.php in core/modules/system/tests/src/Functional/UpdateSystem/UpdateScriptTest.php
UpdatesWith7xTest.php in core/modules/system/tests/src/Functional/UpdateSystem/UpdatesWith7xTest.php

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.