code: public MessageDeliveryStatus messageArrived(final Message message) {
          if (!this.hasToLetMessageThroughTheGate(message)) {
              return null;
          }
          final boolean messageAccepted = this.storage.registerMessage(message, this);
          final MessageDeliveryStatus status = messageAccepted ? MessageDeliveryStatus.ACCEPTED
                  : MessageDeliveryStatus.REJECTED;
          this.consumers.messageReceived(message, status, this);
          return status;
      }
docs: Notify {@link MessageConsumer}s of a message that is either
  {@link MessageDeliveryStatus#ACCEPTED} or
  {@link MessageDeliveryStatus#REJECTED}.
  
  @param message
  The message in question.
  @return Null if stopped at the gate by
  {@link LogWatchBuilder#getGateCondition()},
  {@link MessageDeliveryStatus#ACCEPTED} if accepted in
  {@link LogWatchBuilder#getStorageCondition()},
  {@link MessageDeliveryStatus#REJECTED} otherwise.