@Override
  public CheckResult check() {
    try {
      start();
      CheckResult failure = connection.failure.get();
      if (failure != null) return failure;
      return CheckResult.OK;
    } catch (Throwable e) {
      Call.propagateIfFatal(e);
      return CheckResult.failed(e);
    }
  }
Queue zipkin spans will be consumed from. Defaults to "zipkin-spans".
zipkin-collector/rabbitmq/src/main/java/zipkin2/collector/rabbitmq/RabbitMQCollector.java