Where are my processing instructions?

[Juan Carlos Sánchez Mariñas]

Hi.       First of all, I think this is a basic question but I just do not know to do it, and I don't see it in the documentation.       I'm loading a basic xml from a file using XercesDOMParser::parse.     Example basic xml:         <?xml version="1.0" encoding="UTF-8"?>            <Objet/>       Later I try to save it to another file using DOMWriter::writeNode, the PI's are lost.           New file:                <Objet/>       What is the correct way to do it?   Thanks.