--- /dev/null
+<?php
+
+namespace Drupal\contextual_test\Controller;
+
+/**
+ * Test controller to provide a callback for the contextual link.
+ */
+class TestController {
+
+ /**
+ * Callback for the contextual link.
+ *
+ * @return array
+ * Render array.
+ */
+ public function render() {
+ return [
+ '#type' => 'markup',
+ '#markup' => 'Everything is contextual!',
+ ];
+ }
+
+}