private Optional<BftEvent> nextEvent() {
    try {
      return Optional.ofNullable(incomingQueue.poll(500, TimeUnit.MILLISECONDS));
    } catch (final InterruptedException interrupt) {
      // If the queue was interrupted propagate it and spin to check our shutdown status
      Thread.currentThread().interrupt();
      return Optional.empty();
    }
  }
Await stop.

@throws InterruptedException the interrupted exception
consensus/common/src/main/java/org/hyperledger/besu/consensus/common/bft/BftProcessor.java