Add TODO comment to XmlStringBuilder

smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java

@@ -269,6 +269,7 @@ public class XmlStringBuilder implements Appendable, CharSequence, Element {
 
     public XmlStringBuilder attribute(String name, Enum<?> value) {
         assert value != null;
+        // TODO: Should use toString() instead of name().
         attribute(name, value.name());
         return this;
     }