code: @Override
      public boolean subscribe(IConsumer consumer, Map<String, Object> paramMap) {
          if (consumer instanceof IPushableConsumer) {
              boolean success = super.subscribe(consumer, paramMap);
              if (log.isDebugEnabled()) {
                  log.debug("Consumer subscribe{} {} params: {}", new Object[] { (success ? "d" : " failed"), consumer, paramMap });
              }
              if (success) {
                  fireConsumerConnectionEvent(consumer, PipeConnectionEvent.EventType.CONSUMER_CONNECT_PUSH, paramMap);
              }
              return success;
          } else {
              throw new IllegalArgumentException("Non-pushable consumer not supported by PushPushPipe");
          }
      }
docs: {@inheritDoc}