I need support for computed properties in App Engine. I downloaded the latest source release to try and implement them myself. Whilst going through code, I came across a property class that already seems to do exactly what I need.
class ComputedProperty(Property):
  """Property used for creating properties derived from other values.
  Certain attributes should never be set by users but automatically
  calculated at run-time from other values of the same entity.  These
  values are implemented as persistent properties because they provide
  useful search keys.
  ...
  """
The problem that it's undocumented; I can't find anything about ComputedProperty in the official docs. 
So is ComputedProperty safe to use or is it buggy or/and subject to change?