Do a copy of the node to a given document.

def docCopyNode(self, doc, extended):
        """Do a copy of the node to a given document. """
        if doc is None: doc__o = None
        else: doc__o = doc._o
        ret = libxml2mod.xmlDocCopyNode(self._o, doc__o, extended)
        if ret is None:raise treeError('xmlDocCopyNode() failed')
        __tmp = xmlNode(_obj=ret)
        return __tmp