public void removeRemotable(Remotable remotable) {
   log.debug("removeRemotable " + remotable);
   Remotable previous = remotables.remove(remotable.getId());
   assert previous == remotable
       : "there was a different remotable under "
           + remotable.getId()
           + " ("
           + previous
           + " != "
           + remotable
           + ")";
 }
 public void addRemotable(Remotable remotable) {
   log.debug("addRemotable " + remotable);
   Remotable previous = remotables.put(remotable.getId(), remotable);
   assert previous == null : "there was a previous remotable under " + remotable.getId();
 }