+ walkTreeInPreOrderEmptyFolder($index, $imap_stream, $tree, $trash_folder);
+}
+
+/**
+ * Recursively walk the tree of mailboxes in the given folder and delete all folders and messages
+ *
+ * @param int index the place in the tree to start, usually 0
+ * @param stream imap_stream the IMAP connection to send commands to
+ * @param array tree the tree to walk
+ * @param mailbox the name of the root folder to empty
+ * @return void
+ */
+function walkTreeInPreOrderEmptyFolder($index, $imap_stream, $tree, $mailbox) {