Timeout is an option of `waitFor`, not `then`

notebook/tests/util.js

@@ -166,11 +166,11 @@ casper.wait_for_output = function (cell_num, out_num) {
             },
             // pass parameter from the test suite js to the browser code js
             {c : cell_num, o : out_num});
+        },
+        function then() { },
+        function timeout() {
+            this.echo("wait_for_output timed out!");
         });
-    },
-    function then() { },
-    function timeout() {
-        this.echo("wait_for_output timed out!");
     });
 };