Parsing the XML here is okay, quick-and-dirty, short-term solution.  However, it can be problematic in the long-term because it will report failed matches on otherwise valid XML.  For example:

    <graphic someattr=value other=value passwd=whatever/>

I will add a TODO on our wiki page to subclass ``VMXML`` to ``Snapshot`` class that can handle disk, memory and system types (or maybe three subclasses).  Maybe someone else (or myself) will pick it up, and we can switch this test to use more robust comparisons.  What you have here is fine for now, assuming you don't have ten more snapshot tests lined up behind this one :D