code: public void addDispatcher(String dispatcherId, AbsActorDispatcher dispatcher) {
          synchronized (dispatchers) {
              if (dispatchers.containsKey(dispatcherId)) {
                  return;
              }
              dispatchers.put(dispatcherId, dispatcher);
          }
      }
docs: Registering custom dispatcher
  
  @param dispatcherId dispatcher id
  @param dispatcher   dispatcher object