Create an xmltextReader for a preparsed document.

def readerWalker(self):
        """Create an xmltextReader for a preparsed document. """
        ret = libxml2mod.xmlReaderWalker(self._o)
        if ret is None:raise treeError('xmlReaderWalker() failed')
        __tmp = xmlTextReader(_obj=ret)
        return __tmp