code: def replaceNode(self, cur):
          
          if cur is None: cur__o = None
          else: cur__o = cur._o
          ret = libxml2mod.xmlReplaceNode(self._o, cur__o)
          if ret is None:raise treeError('xmlReplaceNode() failed')
          __tmp = xmlNode(_obj=ret)
          return __tmp
docs: Unlink the old node from its current context, prune the new
            one at the same place. If @cur was already inserted in a
             document it is first unlinked from its existing context.