+ * Note: Currently this will create the directory object if it doesn't
+ * exist. In the future, when a directory object does not exist this
+ * will return NOTMUCH_STATUS_SUCCESS and set *directory to NULL.
+ * Callers should be prepared for this.
+ *
+ * Return value:
+ *
+ * NOTMUCH_STATUS_SUCCESS: Successfully retrieved directory.
+ *
+ * NOTMUCH_STATUS_NULL_POINTER: The given 'directory' argument is NULL.
+ *
+ * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred;
+ * directory not retrieved.
+ *
+ * NOTMUCH_STATUS_READ_ONLY_DATABASE: Database was opened in read-only
+ * mode so the directory cannot be created (this case will be
+ * removed in the future).