title: Problem with JSONValue
body: <p>Am I totally missing something here?  Why can't I get out what I'm putting in?</p>
  
  <pre><code>Set&lt;String&gt; stringSet = new LinkedHashSet&lt;String&gt;();
  stringSet.add("firstName");
  Map&lt;String,Object&gt; payload = new LinkedHashMap&lt;String,Object&gt;();
  payload.put("properties", stringSet);
  
  String sPayload = JSONValue.toJSONString(payload);
  payload = (Map&lt;String, Object&gt;) JSONValue.parse(sPayload); // &lt;-- payload == NULL
  </code></pre>