[castor-user] setup root attibutes

[SH SERVICE WEB]

hi,
the question is: 
Why when I marshal,  the root element don't have the same root attributes such 
.xsd file?

example:

xsd: 
< MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xsi:noNamespaceSchemaLocation="MyXsd.xsd">

castor:
<MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xsi:type="MyClass">

How I can obtain the same element attributes?

Thank's
Antonio Donia