It looks like a simple conversion to HashMap is possible.
I'll fix this since I'm working in the area atm.
2007-06-05 Mike Cvet <email@example.com>
* hpd/CLI.java: Turned Hashtables into HashMaps. Fixes #3986.
(StepHandler): Added. Handler for line stepping. Fixes #4594.
(StepInstructionHandler): Added. Handler for instruction steping.
(WhereHandler.handle): Bail immediately if the process is running.
(GoHandler.handle): Sets running boolean.
(HaltHandler.handle): Unsets running boolean.
(CLI): Added new stepping handlers.