13 files declare their use of AccessResultInterface

AccessibleTestingTrait.php in core/modules/block_content/tests/src/Unit/Access/AccessibleTestingTrait.php
AccessResultTest.php in core/tests/Drupal/Tests/Core/Access/AccessResultTest.php
Contains \Drupal\Tests\Core\Access\AccessResultTest.
BlockPluginHasSettingsTrayFormAccessCheckTest.php in core/modules/settings_tray/tests/src/Unit/Access/BlockPluginHasSettingsTrayFormAccessCheckTest.php
Element.php in core/lib/Drupal/Core/Render/Element.php
EntityAccessDeniedHttpException.php in core/modules/jsonapi/src/Exception/EntityAccessDeniedHttpException.php
FieldResolver.php in core/modules/jsonapi/src/Context/FieldResolver.php
FormBuilder.php in core/lib/Drupal/Core/Form/FormBuilder.php
MediaAccessControlHandlerTest.php in core/modules/media/tests/src/Kernel/MediaAccessControlHandlerTest.php
MenuLinkContentEntityAccessTest.php in core/modules/menu_link_content/tests/src/Unit/MenuLinkContentEntityAccessTest.php
MenuLinkTree.php in core/lib/Drupal/Core/Menu/MenuLinkTree.php
Renderer.php in core/lib/Drupal/Core/Render/Renderer.php
RendererTest.php in core/tests/Drupal/Tests/Core/Render/RendererTest.php
Contains \Drupal\Tests\Core\Render\RendererTest.
ResourceResponseTestTrait.php in core/modules/jsonapi/tests/src/Functional/ResourceResponseTestTrait.php

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