public void printCacheState(CellRegion region, PrintWriter pw, Locus locus) {
   ACTOR.execute(handler, new PrintCacheStateCommand(region, pw, locus));
 }
 private Object execute(Command command) {
   return ACTOR.execute(handler, command);
 }
 public <T> T execute(Command<T> command) {
   return ACTOR.execute(handler, command);
 }