bitemporal + unitemporal objects (data or module!) + contexts in python+sqlalchemy, with or without dbcook; +some attempt at history-enabled attributes
addon (mixin-class) for objects that have 2-time-history and state( enabled/disabled) needs following properties per object:
obj_id = ObjId() #incremented by special ObjectCounter
time_valid = someDate()
time_trans = someDate()
disabled = Bool( default_value= False)
Has very thorough tests, and library of related things like support of time-versioned src-modules, TimeContext etc.
svilen dobrev + stefan boyadzhiev ~2006-7