6 files declare their use of RenderableInterface

Breadcrumb.php in core/lib/Drupal/Core/Breadcrumb/Breadcrumb.php
ExampleRenderable.php in core/modules/system/tests/modules/twig_theme_test/src/ExampleRenderable.php
FormattedDateDiff.php in core/lib/Drupal/Core/Datetime/FormattedDateDiff.php
Link.php in core/lib/Drupal/Core/Link.php
TwigExtension.php in core/lib/Drupal/Core/Template/TwigExtension.php
TwigExtensionTest.php in core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php

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