code: public static boolean unregister(IEventHandler who) {
          final Handle handle = Handle.getInstance();
          return handle._unregister(who);
      }
docs: Unregisters an {@link IEventHandler}
  @param who {@link IEventHandler} that wish to be unregistered
  @return true if {@link IEventHandler} was unregistered
  false if {@link IEventHandler} was not registered with this bus