internal ManyToOneConcurrentArrayQueueDispatcher(
     int mailboxSize,
     long fixedBackoff,
     int throttlingCount,
     int totalSendRetries)
 {
     backoff = fixedBackoff == 0L ? new Backoff() : new Backoff(fixedBackoff);
     RequiresExecutionNotification = fixedBackoff == 0L;
     Mailbox = new ManyToOneConcurrentArrayQueueMailbox(this, mailboxSize, totalSendRetries);
     this.throttlingCount = throttlingCount;
     closed = new AtomicBoolean(false);
 }
 internal ManyToOneConcurrentArrayQueueDispatcher(
     int mailboxSize,
     long fixedBackoff,
     int throttlingCount,
     int totalSendRetries)
 {
     backoff = fixedBackoff == 0L ? new Backoff() : new Backoff(fixedBackoff);
     RequiresExecutionNotification = fixedBackoff == 0L;
     Mailbox = new ManyToOneConcurrentArrayQueueMailbox(this, mailboxSize, totalSendRetries);
     this.throttlingCount = throttlingCount;
     closed = new AtomicBoolean(false);
     dispatcherTokenSource = new CancellationTokenSource();
     backoffTokenSource    = CancellationTokenSource.CreateLinkedTokenSource(dispatcherTokenSource.Token);
 }