how to parse squeak object to xml

> for example i have
>
> schoolClassName
>
>    - student
>    -
>       - name: firstname
>    - surname: firstsurname
>    - mark: 6...
>    - student
>    -
>       -    name: firstname1
>    -    surname: firstsurname1
>    -    mark: 7...
>
>
>    - student
>    -
>       -    name: firstname2
>    -    surname: firstsurname2
>    -    mark: 5..
>
>
>
>    - etc.
>
> is where some written methods which parse any structure object  to xml  
> file.
>
> could anyone give simple example, how to do it.
> or there is no simple example :(
>
> i saw some packages, but have no idea how to get started using them..
>
> or should i write it by myself :)