Container in MS VISIO

If someone knows how to place one figure 开发者_运维百科inside another in Visio VDX (xml) format, please provide explanation (or link) and xml code sample. Thank you.

I found something that helps but not too much:

http://blogs.msdn.com/b/visio/archive/2010/01/12/custom-containers-lists-and-callouts-in-visio-2010.aspx

In short by reading User.msvStructureType element from shape element, we can at least find out which shapes are containers and which are not. But there is no hierarchy info as far I can see...