thin <CODE>
GenClass</CODE>
 are available for use by any generic object. Several subclasses of <CODE>
GenClass </CODE>
also contain their own ATTR vardata entries. In <CODE>
GenClass</CODE>
 no vardata attributes or hints are set by default.</P>
<P>
ATTRs often behave as additional instance data that just happens to be vardata (and therefore optionally added). For generic objects, these should always be considered part of the generic state of an object and therefore may be saved out to the state file. You 