? when assigned alias name doesn't overwrite the class name

I don't know if it's a bug for sure but I have a case where the alias I assign doesn't get applied but instead the class name is included into the generated XML.

public class XMLTemplate {
static XStream xstream = new XStream();

...

but in XML it produces

<?xml version="1.0" encoding="UTF-8"?>
<test.PHRInfo>
<personalInfo>
<contact>
<firstName>Lorry</firstName>
<email />
</contact>
<dob />
<sex />
<note />
</personalInfo>
<emergencyInfo>
<list>
<test.EmergencyContact>
<contact>
<firstName>ggg</firstName>
<phone />
<cell />
</contact>
<relation />
</com.inzami.phr.EmergencyContact>
...

Can you tell why the alias for com.inzami.phr.PHRInfo and com.inzami.phr.EmergencyContact do not get applied?