- * Returns: (array zero-terminated=1) (transfer full): a null-terminated array of strings of all of the
- * possible attribute types for the given @name_space, or
- * %NULL on error.
+ * Returns: (nullable) (array zero-terminated=1) (transfer full): a
+ * null-terminated array of strings of all of the possible attribute
+ * types for the given @name_space, or %NULL on error.