Add .api.php file to document hook_simple_sitemap_links_alter()

simple_sitemap.api.php

+<?php
+/**
+ * @file
+ * Hooks provided by the Simple XML sitemap module.
+ */
+
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * Alter the generated link data before the sitemap is saved.
+ * This hook gets invoked for every sitemap chunk generated.
+ *
+ * @param array &$links
+ *  Array containing multilingual links generated for each path to be indexed.
+ */
+function hook_simple_sitemap_links_alter(&$links) {
+  // Remove German links for all paths in the hreflang sitemap.
+  foreach($links as &$link) {
+    unset($link['urls']['de']);
+  }
+}
+
+/**
+ * @} End of "addtogroup hooks".
+ */
+