Issue #2049039 by Berdir: Convert node properties to methods.

core/includes/menu.inc

core/includes/theme.inc

core/modules/action/lib/Drupal/action/Tests/BulkFormTest.php

core/modules/book/book.module

core/modules/comment/comment.module

...ules/comment/lib/Drupal/comment/CommentFormController.php

...mment/lib/Drupal/comment/Controller/CommentController.php

...comment/lib/Drupal/comment/Plugin/Core/Entity/Comment.php

...les/comment/lib/Drupal/comment/Tests/CommentLinksTest.php

...ment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.php

...omment/lib/Drupal/comment/Tests/CommentStatisticsTest.php

...ment/lib/Drupal/comment/Tests/CommentTokenReplaceTest.php

...ent/lib/Drupal/comment/Tests/CommentTranslationUITest.php

...omment/lib/Drupal/comment/Tests/Views/CommentTestBase.php

.../Drupal/comment/Tests/Views/DefaultViewRecentComments.php

core/modules/datetime/datetime.module

...lib/Drupal/entity_reference/Tests/Views/SelectionTest.php

...ules/file/lib/Drupal/file/Tests/FileFieldRevisionTest.php

.../modules/file/lib/Drupal/file/Tests/FileFieldTestBase.php

core/modules/file/lib/Drupal/file/Tests/FileListingTest.php