toObject fixes

src/Node.js

@@ -1231,7 +1231,7 @@
 
       for (key in attrs) {
         val = attrs[key];
-        getter = this[key];
+        getter = typeof this[key] === 'function' && this[key];
         // remove attr value so that we can extract the default value from the getter
         delete attrs[key];
         defaultValue = getter ? getter.call(this) : null;