batch.scala

batch match {
 // this is the first of the batch
 case Nil =>
  // add this payment to the batch
  context.become(ready(accnKey, accn, replyTo, Seq(payment)))
  // remind myself in 1 second from now to flush the batch
  context.system.scheduler.scheduleOnce(1.second, self, Flush)

 // this is the last that can fit inside the batch
 case _ if batch.size == MaxTxnLength - 1 =>
  // transact the batch right now
  transmit(payment +: batch)
  // clear the batch
  context.become(ready(accnKey, accn.withIncSeq, replyTo))

 // it’s not the first payment, nor the last
 case _ =>
  // add this payment to the batch
  context.become(ready(accnKey, accn, replyTo, payment +: batch))
}