indexing description: "TODO" date: "$Date$" revision: "$Revision$" class TAPE_ARCHIVE create make feature {NONE} make -- TODO do create tape is_loaded := tape /= Void ensure tape_created: tape /= Void loaded: is_loaded end feature tape: TAPE -- TODO is_loaded: BOOLEAN -- TODO eject do tape := Void is_loaded := False ensure tape = Void not is_loaded end store (o: ANY) -- TODO require o /= Void is_loaded do tape.save (o) end invariant is_loaded implies tape /= Void end