--- /dev/null
+<?php
+
+/**
+ * @file
+ * Mock module for testing simpletest.
+ */
+
+/**
+ * Implements hook_simpletest_alter().
+ *
+ * This hook is deprecated and should trigger a deprecation error when invoked.
+ */
+function simpletest_deprecation_test_simpletest_alter(&$groups) {
+ // No-op.
+}