code: @Override
      public void subscribe(String channel, ISubscriber<ID, DATA> subscriber) {
          try {
              WrapAroundSubscriber wrap = subscriptions.get(channel).get(subscriber,
                      new Callable<WrapAroundSubscriber>() {
                          @Override
                          public WrapAroundSubscriber call() throws Exception {
                              return new WrapAroundSubscriber(channel, subscriber);
                          }
                      });
              eventBus.get(channel).register(wrap);
          } catch (ExecutionException e) {
              throw new RuntimeException(e);
          }
      }
docs: {@inheritDoc}