6 files declare their use of ModuleUninstallValidatorInterface

BookUninstallValidator.php in core/modules/book/src/BookUninstallValidator.php
ContentUninstallValidator.php in core/lib/Drupal/Core/Entity/ContentUninstallValidator.php
CoreServiceProvider.php in core/lib/Drupal/Core/CoreServiceProvider.php
FilterUninstallValidator.php in core/modules/filter/src/FilterUninstallValidator.php
ForumUninstallValidator.php in core/modules/forum/src/ForumUninstallValidator.php
ModuleInstallerTest.php in core/tests/Drupal/KernelTests/Core/Extension/ModuleInstallerTest.php

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