[xml] saving node to a buffer

[Roger Reynolds <rogerr softix com>]

Given a node in a tree, how does one obtain a string which would represent
the "outer xml" for the node, if you know what I mean?
(by outer xml, I mean an xml element that represents this node and it's
 children, contrasted with the "inner xml" which I believe would be
equivalent
  to the "content" member of this node, right?)

I started out to use xmlSaveToBuffer to create a save context
to use with xmlSaveTree, however in version 2.6.8 this function, 
although documented, is not implemented.

There's got to be a way, right?

Thanks in advance..

roger