Setting values to <s:any/> with XMLObject

One of my XSD document have <s:any/> as a type. If I have a XMLObject
constructed, how could I set it?

<s:element maxOccurs="1" minOccurs="0" name="Request">
       <s:complexType>
        <s:sequence>
         <s:any/>
        </s:sequence>
       </s:complexType>
</s:element>

This doesn't seem to work...

Request request = Request.Factory.newInstance();
request.set(anotherXmlObject);