he Java object tree with root object <code>object</code> to a String
 instance as JSON.</div>
<dl>
<dt><span class="paramLabel">Parameters:</span></dt>
<dd><code>object</code> - The root object of the object content tree to be serialized. Must not be null.</dd>
<dd><code>runtimeType</code> - Runtime type of the content tree's root object.</dd>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>String instance with serialized JSON data.</dd>
<dt><span class="throwsLabel">Throws:</span></dt>
<dd><code><a 