parse an XML file from the filesystem or the network. This
           reuses the existing @ctxt parser context

def htmlCtxtReadFile(self, filename, encoding, options):
        """parse an XML file from the filesystem or the network. This
           reuses the existing @ctxt parser context """
        ret = libxml2mod.htmlCtxtReadFile(self._o, filename, encoding, options)
        if ret is None:raise treeError('htmlCtxtReadFile() failed')
        __tmp = xmlDoc(_obj=ret)
        return __tmp